Search

The aim of this paper is to present a patient with the Smith-Lemli-Opitz syndrome (SLOS), with an overview of the modality of diagnosis, and the treatment of the patient. Exome analysis showed two variants in exon 6 of the 7-dehydrocholesterol reductase (DHCR7) gene have been determined: missense variant 1) NM_001360.2: c.470T>C (p.Leu157Pro) and 2) nonsense variant c.452G>A (W151*). Therefore the DHCR7 genotype of the patient is NM_001360.2: c.[470T>C; c.452G>A]. The proband, aged 6 years, has global developmental retardation with missing contact gaze and lacking motor development for her age and with peripheral spastic-enhanced muscle tone, and is under the supervision of children neurologists, gastroenterologists, nephrologists and cardiologists.

BACKGROUND We sought to determine the incidence of Fabry disease (FD) in young cryptogenic stroke patients who lived in the City of Edirne, Turkey, and to define the clinical features helping to recognize patients with FD. METHODS Acute ischemic stroke patients aged 18 to 55 years who were admitted to our hospital between January 2017 and September 2019 were evaluated for inclusion. The screening was performed for α-galactosidase A activity on dried blood spot, and DNA was sequenced for GLA mutation in patients with low-plasma α-galactosidase A activity. RESULTS Two proband cases were detected. The first proband patient was identified as having a 427G>A (rs 104894845) (p.A143T) hemizygous mutation along with his family; 3 patients were identified as having the same hemizygous mutation; and 6 patients were identified as having the same heterozygous mutations. The second proband patient was identified as having a c.352C>T (rs 148158093) (p.R118C) heterozygote mutation along with her family; 5 patients were identified as having the same heterozygote mutation; and 1 patient was identified as having the same hemizygous mutation. Our study identified the FD incidence as 3.27%. CONCLUSIONS This research is just one of a few studies conducted on FD screening studies in Turkish stroke patients. Our results underlined the importance of considering FD during the etiologic evaluation of young cryptogenic stroke patients, as it is a rare but potentially treatable entity.

Menkes disease (MD) is a rare congenital copper deficiency disease caused by an adenosine triphosphatase copper transporting alpha (ATP7A) gene mutation. It is a progressive and systemic disease that primarily involves the central nervous system and connective tissues. The clinical manifestation of these patients with MD is curly hair, progressive muscle tone reduction, and convulsions, and often leads to death in early infancy. Herein, we present a case of a 9-month-old Chinese male who displayed developmental regression, followed by convulsions, which were characterized by infantile spasms (ISs). The proband also had curly hair, hypopigmented skin, cutis laxa, decreased muscle tone, and micrognathia. The patient’s ceruloplasmin levels were below the reference values. Brain magnetic resonance imaging (MRI) showed abnormal signals bilaterally that were symmetrically distributed in the caudate nucleus, globus pallidus, and subcortical white matter of the temporal parietal cortex, white matter in the anterior and posterior corners of the ventricles and the anterior limb of the internal capsule. The electroencephalograph (EEG) showed hypsarrhythmia. Genetic testing revealed a novel frameshift mutation in the ATP7A gene exon 13 and premature termination codon. Copper replacement therapy was initiated after the delayed diagnosis was established. However, the patient still died several months later due to disease progression. Our case reveals a novel frameshift mutation of the ATP7A gene, which expands the gene spectrum of MD. The infants with uncontrollable convulsions, regressive development, curly hair, MD should be considered at early stage and also need the further genetic analysis to confirm MD finally. The correct and timely diagnosis and initiating copper replacement therapy may improve the prognosis.

Background LCAT (lecithin-cholesterol acyltransferase) deficiency is characterized by two distinct phenotypes, familial LCAT deficiency (FLD) and Fish Eye disease (FED). This is the first systematic review evaluating the ethnic distribution of LCAT deficiency, with particular emphasis on Latin America and the discussion of three Mexican-Mestizo probands. Methods A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic review and Meta-Analysis) Statement in Pubmed and SciELO. Articles which described subjects with LCAT deficiency syndromes and an assessment of the ethnic group to which the subject pertained, were included. Results The systematic review revealed 215 cases (154 FLD, 41 FED and 20 unclassified) pertaining to 33 ethnic/racial groups. There was no association between genetic alteration and ethnicity. The mean age of diagnosis was 42 ± 16.5 years, with fish eye disease identified later than familial LCAT deficiency (55 ± 13.8 vs. 41 ± 14.7 years respectively). The prevalence of premature coronary heart disease was significantly greater in FED vs. FLD. In Latin America, 48 cases of LCAT deficiency have been published from six countries (Argentina (1 unclassified), Brazil (38 FLD), Chile (1 FLD), Columbia (1 FLD), Ecuador (1 FLD) and Mexico (4 FLD, 1 FED and 1 unclassified). Of the Mexican probands, one showed a novel LCAT mutation. Conclusions The systematic review shows that LCAT deficiency syndromes are clinically and genetically heterogeneous. No association was confirmed between ethnicity and LCAT mutation. There was a significantly greater risk of premature coronary artery disease in fish eye disease compared to familial LCAT deficiency. In FLD, the emphasis should be in preventing both cardiovascular disease and the progression of renal disease, while in FED, cardiovascular risk management should be the priority. The LCAT mutations discussed in this article are the only ones reported in the Mexican- Amerindian population.

The sortilin-related receptor 1 (SORL1) gene has been the subject of many studies focusing on frequent polymorphisms, which is associated with increased risk for Alzheimer’s Disease (AD). By whole-exome sequencing (WES), we identified two pathogenic missense mutations c.579C > G (p.F193L) and c.1397A > G (p.N466S) in SORL1. The two mutations were located in the same protein domain, and the two unrelated probands both had an onset of memory problems at less than 65 years of age, but their clinical manifestations and cranial imaging are different. The protein structure and function affected by these mutations were predicted using bioinformatics analysis, which suggested they were pathogenic. 3D protein structural analysis revealed that these amino acid substitutions might result in instability of protein structure and adverse intramolecular interactions. These findings suggest that both F193L and N466S should be thought as potential causative mutations in early-onset Alzheimer’s disease (EOAD) patients. Further functional studies are warranted to evaluate their roles in the pathogenesis of AD.

Background Alport syndrome and C3 glomerulonephritis (C3GN) are rare kidney diseases, frequently responsible for familial haematuria, proteinuria, and renal impairment. With the rapid development of molecular genetic testing, Alport syndrome causes have been restricted mostly to variants in the COL4A5 or COL4A3/COL4A4 genes. Moreover, a broad range of genetic contributors in the complement and complement-regulating proteins are definitely implicated in the pathogenesis of C3GN. Methods We sought a family with persistent microscopic haematuria associated with renal failure. Clinicopathologic and follow-up data were obtained, and molecular genetic testing was used to screen for pathogenic variants. Results We describe a three-generation family with Alport syndrome showing a dominant maternal inheritance. Notably, renal biopsy showed the concurrent histological evidence of C3GN in the proband harbouring an uncommon heterozygous variation in CFHR5, c.508G > A. The alteration leads to replacement of a highly conserved residue at position 170 of the β-strand subunit of CFHR5 (p.Val170Met). In silico analysis showed that the variation was predicted to deregulate complement activation by altering the structural properties and enhancing C3b binding capacity to compete with Complement Factor H (CFH), which was in line with experimental data previously published. Conclusions The comorbidity findings between Alport syndrome and C3GN indicate an underlying overlap and require further study.

Here we report the first familial case spread through at least three generations, genetically verified cases of Marshall-Stickler syndrome in Bulgaria. The proband, a 2-year-old girl, has craniofacial dysplasia, ocular hypertelorism, small saddle nose with a flat bridge and midface hypoplasia. The pedigree of the proband’s family showed that her father has the same clinical manifestations of the disease. In addition, her father presented with a tall, thin stature and mild hearing loss, manifested with aging. The same dysmorphological symptoms were presented by the paternal grandfather. Both patients, the 2-year-old girl and her father, have been diagnosed to carry Marshall-Stickler syndrome. The COL2A1 gene tested negative in the family. Based on the higher percentage of mutations in the COL2A1 gene, we analyzed this gene as the first target in the family. The COL2A1 gene tested negative, and we sequenced the gene further. A novel splice site mutation c.3474+1G>A was found in intron 44. This variant is related to the clinical presentation in the patient and her father. The c.3474+1G>A mutation results in altered splicing affects at the donor splice site of intron 44, which most probably gives a nonfunctional protein. The variant affects the major triple-helical domain that represents a mutation hot-spot for the gene.

X-linked juvenile retinoschisis is a hereditary eye disease that belongs to the group of retinal dystrophy. This study presents the results of the search for mutations in the RS1 gene in 48 unrelated men diagnosed with X-linked juvenile retinoschisis. Molecular genetic diagnosis was found in 77% of the probands. Revealed were 27 different pathogenic variants, including eight novel, previously not described. The spectrum of mutations in the RS1 gene in a Russian cohort of patients is characterized by high diversity and the absence of major mutations.

Congenital heart defects, one of the most common birth defects, affect approximately 1% of live birth globally and remain the leading cause of infant mortality in developed countries. Utilizing the pathogenicity score and inheritance mode from whole exome sequencing results, a heterozygous mutation (NM_001278939.1: c.1939G>T, p.Gly647Ter) in elastin (ELN) was identified among 6,440 variants in a female proband born with an atrial septal defect accompanied by pulmonary artery stenosis. Results of RT-PCR showed that the mutation (NM_001278939.1: c.1939G>T, p.Gly647Ter) did not affect the expression levels of ELN mRNA but increased protein level. The content of ELN truncate (functional component) was significantly lower in both the intracellular and extracellular compartments after mutation. These results indicate that the ELN mutation (NM_001278939.1: c.1939G>T, p.Gly647Ter) affected the protein truncate, which may be a functional component of ELN and play crucial roles for this pedigree. Here we report of an ELN heterozygous variant associated with congenital heart disease accompanied with pulmonary artery stenosis, which is less common. Based on our results, we speculate that this may be the main molecular mechanism underlying the mutation-led functional changes, and propose that the decrease of ELN protein level may cause this pedigree vascular abnormality, especially pulmonary artery stenosis, and reinforce the view that ELN insufficiency is the primary cause of these vascular lesions. This may be the main molecular mechanism underlying the mutation-led functional changes. Thus, systematic analysis not only enables us to better understand the etiology of this disease but also contributes to clinical and prenatal diagnosis.

Pathogenic variants in MYH7 cause a wide range of cardiac and skeletal muscle diseases with childhood or adult onset. These include dilated and/or hypertrophic cardiomyopathy, left ventricular non-compaction cardiomyopathy, congenital myopathies with multi-minicores and myofiber type disproportion, myosin storage myopathy, Laing distal myopathy and others (scapulo-peroneal or limb-girdle muscle forms). Here we report the results from molecular genetic analyses (NGS and Sanger sequencing) of 4 patients in two families with variable neuromuscular phenotypes with or without cardiac involvement. Interestingly, variants in MYH7 gene appeared to be the cause in all the cases. A novel nonsense variant c.5746C>T, p.(Gln1916Ter) was found in the patient in Family 1 who deceased at the age of 2 years 4 months with the clinical diagnosis of dilated cardiomyopathy, whose father died before the age of 40 years, due to cardiac failure with clinical diagnosis of suspected limb-girdle muscular dystrophy. A splice acceptor variant c.5560–2A>C in MYH7 was detected in the second proband and her sister, with late onset distal myopathy without cardiac involvement. These different phenotypes (muscular involvement with severe cardiomyopathy and pure late onset neuromuscular phenotype without heart involvement) may result from novel MYH7 variants, which most probably impact the LMM (light meromyosin) domain's function of the mature protein.

BACKGROUND. Genetic defects of innate immunity impairing intestinal bacterial sensing are linked to the development of Inflammatory Bowel Disease (IBD). Although much evidence supports a role of the intestinal virome in gut homeostasis, most studies focus on intestinal viral composition rather than on host intestinal viral sensitivity. AIM. To demonstrate the association between the development of Very Early Onset IBD (VEOIBD) and variants in the IFIH1 gene which encodes MDA5, a key cytosolic sensor for viral nucleic acids. METHODS. Whole exome sequencing (WES) was performed in two independent cohorts of children with VEOIBD enrolled in Italy (n=18) and USA (n=24). Luciferase reporter assays were employed to assess MDA5 activity. An enrichment analysis was performed on IFIH1 comparing 42 VEOIBD probands with 1527 unrelated individuals without gastrointestinal or immunological issues. RESULTS. We identified rare, likely loss-of-function (LoF), IFIH1 variants in eight patients with VEOIBD from a combined cohort of 42 children. One subject, carrying a homozygous truncating variant resulting in complete LoF, experienced neonatal-onset, pan-gastrointestinal, IBD-like enteropathy plus multiple infectious episodes. The remaining seven subjects, affected by VEOIBD without immunodeficiency, were carriers of one LoF variant in IFIH1. Among these, two patients also carried a second hypomorphic variant, with partial function apparent when MDA5 was weakly stimulated. Furthermore, IFIH1 variants were significantly enriched in children with VEOIBD as compared to controls (p=0.007). CONCLUSIONS. Complete and partial MDA5 deficiency is associated with VEOIBD with variable penetrance and expressivity, suggesting a role for impaired intestinal viral sensing in IBD pathogenesis.

Epileptic seizures are a frequent feature of thiamine transporter deficiency that may present as a clinical continuum between severe epileptic encephalopathy and mixed focal or generalized seizures. Thiamine metabolism dysfunction syndrome 2 (MIM: 607483) or biotin-thiamine-responsive basal ganglia disease (BTBGD) due to biallelic pathogenic mutation in the SLC19A3 gene is a well-recognized cause of early infantile encephalopathy with a Leigh syndrome-like presentation and a lesser-known phenotype of atypical infantile spasms. We reported a 4-month-old infant who presented with progressive epileptic spasms since 1 month of age, psychomotor retardation, and lactic acidosis. Magnetic resonance imaging (MRI) revealed altered signal intensities in bilateral thalamic and basal ganglia, cerebellum, brainstem, cortical and subcortical white matter. Whole exome sequencing identified a homozygous ENST00000258403.3: c.871G > C (p.Gly291Arg) variant in the SLC19A3 gene. We elucidate the features in the proband, which were an amalgamation of both the above subtypes of the SLC19A3 associated with early infantile encephalopathy. We also highlight the features which were atypical for either “Leigh syndrome-like” or “atypical infantile spasm” phenotypes and suggest that the two separate entities can be merged as a clinical continuum. Treatment outcome with high-dose biotin and thiamine is promising. In addition, we report a novel pathogenic variant in the SLC19A3 gene.

Purpose: This study aims to demonstrate the possibility of detecting segmental uniparental isodisomy (iUPD) using a next-generation sequencing gene panel by reporting a Leber congenital amaurosis (LCA) case caused by a homozygous pathogenic variant in RPE65 (c.1022 T > C:p.Leu341Ser) inherited exclusively from the proband's mother.Methods: Samples from the trio (proband, mother, and father) were sequenced with a next-generation sequencing (NGS) retinopathy gene panel (224 genes) and the VCF file containing all variants was used in order to determine single nucleotide variant (SNV) counts from each sample across all chromosomes.Results: Trio analysis showed that of 81 Chr1 inherited variants 41 were exclusively maternal, including 21 homozygous. The other 40 variants were common to both parents. On remaining autosomal chromosomes (Chr2-22) 645 inherited variants were found, 147 of them were exclusively maternal and 132 exclusively paternal. Based on these NGS data, it was possible to note that the proband's chromosomes 1 are more similar to his mother's chromosome 1 than his father's, suggesting the pathogenic homozygous variant found in this patient was inherited exclusively from the mother due to uniparental maternal isodisomy.Conclusions: This study presents a secondary analysis pipeline to identify responsible variants for a phenotype and the correct inheritance pattern, which is a critical step to the proper and accurate genetic counseling of all family members. In addition, this approach could be used to determine iUPD in different Mendelian disorders if the sequencing panel identifies variants spread throughout the genome.

Background/AimsThis study aims to assess the contribution of biallelicCPAMD8variants in patients with different forms of glaucoma, especially primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG), based on a systematic analysis of exome sequencing (ES).MethodsPotentially pathogenicCPAMD8variants were selected from the ES data of 5307 subjects with various eye conditions through multiple bioinformatics analyses. Of the 5307 subjects, 1221 probands had different forms of primary glaucoma. The genotype–phenotype correlation was assessed by a systematic review of biallelicCPAMD8variants that including our data and data from the literature. The expression profile ofCPAMD8in human tissues was determined at the mRNA and protein levels.ResultsBiallelicCPAMD8variants, including one frameshift and six missense variants, were exclusively present and significantly enriched in patients with glaucoma (one with juvenile open-angle glaucoma (JOAG), two with POAG and two with PACG) compared with none of the 4086 probands with other eye conditions in this cohort (p=4.1E-07). The effect of variants in these patients is relatively mild compared with that reported in patients with anterior segment dysgenesis or primary congenital glaucoma.CPAMD8mRNA was highly expressed in the optic nerve, ciliary body, retina and iris, whereas the CPAMD8 protein was mainly detected in the nonpigmented epithelium of the iris and ciliary process, determined by immunohistochemistry.ConclusionsThe data from this study not only provide further evidence to support the association of biallelicCPAMD8variants with JOAG but also suggest that biallelicCPAMD8variants might be associated with POAG and PACG.

Usher syndrome, the most prevalent cause of combined hereditary vision and hearing impairment, is clinically and genetically heterogeneous. Moreover, several conditions with phenotypes overlapping Usher syndrome have been described. This makes the molecular diagnosis of hereditary deaf–blindness challenging. Here, we performed exome sequencing and analysis on 7 Mexican and 52 Iranian probands with combined retinal degeneration and hearing impairment (without intellectual disability). Clinical assessment involved ophthalmological examination and hearing loss questionnaire. Usher syndrome, most frequently due to biallelic variants in MYO7A (USH1B in 16 probands), USH2A (17 probands), and ADGRV1 (USH2C in 7 probands), was diagnosed in 44 of 59 (75%) unrelated probands. Almost half of the identified variants were novel. Nine of 59 (15%) probands displayed other genetic entities with dual sensory impairment, including Alström syndrome (3 patients), cone-rod dystrophy and hearing loss 1 (2 probands), and Heimler syndrome (1 patient). Unexpected findings included one proband each with Scheie syndrome, coenzyme Q10 deficiency, and pseudoxanthoma elasticum. In four probands, including three Usher cases, dual sensory impairment was either modified/aggravated or caused by variants in distinct genes associated with retinal degeneration and/or hearing loss. The overall diagnostic yield of whole exome analysis in our deaf–blind cohort was 92%. Two (3%) probands were partially solved and only 3 (5%) remained without any molecular diagnosis. In many cases, the molecular diagnosis is important to guide genetic counseling, to support prognostic outcomes and decisions with currently available and evolving treatment modalities.

We reported a neonate presenting with muscle weakness, hypotonia, and joint contractures since birth. Investigations revealed significantly elevated creatinine-phosphokinase, abnormal electromyography suggestive of muscle disease and normal magnetic resonance imaging (MRI) of the brain. Exome sequencing revealed homozygous pathogenic mutations in LAMA2 (NM_000426.3: c.7881T > G, p.(His2627Gln)) and a heterozygous likely-pathogenic mutation in COL6A2 (NM_001849.3: c.1970–2A > G). Parental segregation by Sanger sequencing confirmed a heterozygous carrier state for the LAMA2 variant in both parents, thus confirming the diagnosis of autosomal recessive LAMA2-muscular dystrophy (LAMA2-MD) in the proband. The COL6A2 variant segregated with the as-yet asymptomatic mother. Musculoskeletal MRI of the proband at 12 months of age revealed peripheral involvement of the vastii, rectus femoris, gastrocnemius and the soleus, with relative central sparing, without areas of fatty infiltration; not serving to distinguish clearly between LAMA-MD and COL6A2- related disease. Reverse phenotyping of a 27-year-old mother revealed a normal musculoskeletal MRI and clinically absent red flags. Potential explanations for the heterozygous likely-pathogenic COL6A2 variant in the proband and the mother include (a) a coexisting diagnosis of autosomal dominant COL6A2-related myopathy, likely Bethlem myopathy, which has a variable clinical phenotype and age of onset; (b) a carrier state for autosomal recessive Ullrich congenital muscular dystrophy; or (c) a heterozygous COL6A2 variant contributing as a synergistic factor along with homozygous LAMA2 mutation. The couple was offered genetic counseling regarding the proband and the future pregnancies.

Context Idiopathic infantile hypercalcemia (IIH), an uncommon disorder characterized by elevated serum concentrations of 1,25 dihydroxyvitamin D (1,25(OH)2D) and low parathyroid hormone (PTH) levels, may present with mild to severe hypercalcemia during the first months of life. Biallelic variants in the CYP24A1 or SLC34A1 genes are associated with severe IIH. Little is known about milder forms. Objective This work aims to characterize the genetic associations and biochemical profile of mild IIH. Methods This is a cross-sectional study including children between age 6 months and 17 years with IIH who were followed in the Calcium Clinic at the Hospital for Sick Children (SickKids), Toronto, Canada. Twenty children with mild IIH on calcium-restricted diets were evaluated. We performed a dietary assessment and analyzed biochemical measures including vitamin D metabolites and performed a stepwise molecular genetic analysis. Complementary biochemical assessments and renal ultrasounds were offered to first-degree family members of positive probands. Results The median age was 16 months. Median serum levels of calcium (2.69 mmol/L), urinary calcium:creatinine ratio (0.72 mmol/mmol), and 1,25(OH)2D (209 pmol/L) were elevated, whereas intact PTH was low normal (22.5 ng/L). Mean 1,25(OH)2D/PTH and 1,25(OH)2D/25(OH)D ratios were increased by comparison to healthy controls. Eleven individuals (55%) had renal calcification. Genetic variants were common (65%), with the majority being heterozygous variants in SLC34A1 and SLC34A3, while a minority showed variants of CYP24A1 and other genes related to hypercalciuria. Conclusion The milder form of IIH has a distinctive vitamin D metabolite profile and is primarily associated with heterozygous SLC34A1 and SLC34A3 variants.

Aims The prognostic value of genetic variants for predicting lethal arrhythmic events (LAEs) in Brugada syndrome (BrS) remains controversial. We investigated whether the functional curation of SCN5A variations improves prognostic predictability. Methods and results Using a heterologous expression system and whole-cell patch clamping, we functionally characterized 22 variants of unknown significance (VUSs) among 55 SCN5A mutations previously curated using in silico prediction algorithms in the Japanese BrS registry (n = 415). According to the loss-of-function (LOF) properties, SCN5A mutation carriers (n = 60) were divided into two groups: LOF-SCN5A mutations and non-LOF SCN5A variations. Functionally proven LOF-SCN5A mutation carriers (n = 45) showed significantly severer electrocardiographic conduction abnormalities and worse prognosis associated with earlier manifestations of LAEs (7.9%/year) than in silico algorithm-predicted SCN5A carriers (5.1%/year) or all BrS probands (2.5%/year). Notably, non-LOF SCN5A variation carriers (n = 15) exhibited no LAEs during the follow-up period. Multivariate analysis demonstrated that only LOF-SCN5A mutations and a history of aborted cardiac arrest were significant predictors of LAEs. Gene-based association studies using whole-exome sequencing data on another independent SCN5A mutation-negative BrS cohort (n = 288) showed no significant enrichment of rare variants in 16 985 genes including 22 non-SCN5A BrS-associated genes as compared with controls (n = 372). Furthermore, rare variations of non-SCN5A BrS-associated genes did not affect LAE-free survival curves. Conclusion In vitro functional validation is key to classifying the pathogenicity of SCN5A VUSs and for risk stratification of genetic predictors of LAEs. Functionally proven LOF-SCN5A mutations are genetic burdens of sudden death in BrS, but evidence for other BrS-associated genes is elusive.

Prader-Willi syndrome (PWS) is a neurogenetic disorder caused by deficiency expression of paternally imprinted genes of the chromosomal region 15. In this study, we report a novel mutation in the myosin binding protein C (MYBPC3) gene in a Prader-Willi syndrome pedigree. Next-generation sequencing (NGS) and Sanger sequencing were performed to define and confirm the MYBPC3 gene mutation. Bioinformatics analysis was also performed for the mutated MYBPC3 protein using available software tools. The proband was diagnosed as PWS with about 4.727Mb copy number missed in the long arm of chromosome 15 and treated with growth hormone on 0.3 IU/day. Sanger sequencing identified a novel heterozygous mutation in the MYBPC3 gene, c.2002C>G (p.R668G). Bioinformatics analysis suggested the variant disease-causing; the Pro residue at 668 in the MYBPC3 protein was highly conserved. Moreover, interactions among MYBPC3 and other proteins suggested the potential effects on the development of cardiomyopathies. This is the first report of PWS with MYBPC3 gene mutation. Besides general examinations, it is vital for physicians to amply molecular genetics to get an accurate diagnosis in the clinic especially for rare diseases.

Correction: A MT-TL1 variant identified by whole exome sequencing in an individual with intellectual disability, epilepsy, and spastic tetraparesis. Eur J Hum Genet. 2021 Sep;29(9):1470-1471. doi: 10.1038/s41431-021-00937-3. The genetic etiology of intellectual disability remains elusive in almost half of all affected individuals. Within the Solve-RD consortium, systematic re-analysis of whole exome sequencing (WES) data from unresolved cases with (syndromic) intellectual disability (n = 1,472 probands) was performed. This re-analysis included variant calling of mitochondrial DNA (mtDNA) variants, although mtDNA is not specifically targeted in WES. We identified a functionally relevant mtDNA variant in MT-TL1 (NC_012920.1:m.3291T > C; NC_012920.1:n.62T > C), at a heteroplasmy level of 22% in whole blood, in a 23-year-old male with severe intellectual disability, epilepsy, episodic headaches with emesis, spastic tetraparesis, brain abnormalities, and feeding difficulties. Targeted validation in blood and urine supported pathogenicity, with heteroplasmy levels of 23% and 58% in index, and 4% and 17% in mother, respectively. Interestingly, not all phenotypic features observed in the index have been previously linked to this MT-TL1 variant, suggesting either broadening of the m.3291T > C-associated phenotype, or presence of a co-occurring disorder. Hence, our case highlights the importance of underappreciated mtDNA variants identifiable from WES data, especially for cases with atypical mitochondrial phenotypes and their relatives in the maternal line. This work was financially supported by Aspasia grants of the Dutch Research Council (015.014.036 to TK and 015.014.066 to LELMV), the European Research Council (ERC to RH), the Well come Investigator Award (109915/Z/15/Z to RH), the Medical Research Council UK (MR/N025431/1 to RH), the Newton Fund (MR/N027302/1 to RH), the Lily Foundation (RH), and the Evelyn Trust (RH). The Solve-RD project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 779257. Sí

AIM: To reveal the importance of TGFBI gene screening for candidates with a family history of corneal disease or granular opacities in corneal stroma before refractive surgery. METHODS: A 37-year-old male (proband) underwent bilateral laser-assisted in situ keratomileusis (LASIK) in 2002, with right vision decreased significantly in 2006. The proband and other 32 members of the family underwent a detailed ophthalmic examination, including vision acuity, intraocular pressure, slit-lamp photograph, fundus examination, optical coherence tomography (OCT) of cornea, and in vivo confocal microscope (IVCM) and peripheral blood was used for genomic DNA extraction. Seventeen TGFBI gene exons were analyzed via polymerase chain reaction amplification and direct sequencing. RESULTS: Slit-lamp, IVCM, and OCT images showed that a large amount of dense and confluent granular opaque were seen at the interfaces of the flap and remnant stromal bed in right and light degree in left eye. Sanger sequencing showed that there was a 371G>A mutation (CGC>CAC) in exon 4, which indicated that he harbored a heterozygote R124H mutation, identifying the diagnosis of Avellino corneal dystrophy (ACD). Among the other 32 family members, 6 of them harbored the identical mutation to that in the proband. CONCLUSION: ACD will worsen and recur after LASIK. Preoperative gene-screening for TGFBI mutations is important in diagnosing ACD.

AIM: To investigate the causal gene mutation and clinical characteristics for two Chinese families with autosomal dominant congenital coralliform cataract. METHODS: Two Chinese pedigrees with congenital cataract were investigated. Routine ophthalmic examinations were performed on all patients and non-affected family members. Peripheral blood samples were collected, and the genomic DNAs were extracted. The coding regions of proband’s DNAs were analyzed with cataract gene panel. The identified mutation was amplified by polymerase chain reaction, and automated sequencing was performed in other members of two families to verify whether the mutated gene was co-segregated with the disease. RESULTS: Congenital coralliform cataract was inherited in an autosomal dominant mode in both pedigrees. For each family, more than half of the family members were affected. All patients presented with severe visual impairment after birth as a result of bilateral symmetric coralliform lens opacification. An exact the same defect in the same gene, a heterozygous mutation of c.70C>A (p. P24T) in exon 2 of γD-crystallin gene, was detected in both probands from each family. Sanger sequencing analysis demonstrated that the mutated CRYGD was co-segregated in these two families. CONCLUSION: A c.70C>A (p. P24T) variant in CRYGD gene was reconfirmed to be the causal gene in two Chinese pedigrees. It is known that mutated CRYGD caused most of the congenital coralliform cataracts, suggesting that the CRYGD gene is associated with coralliform congenital cataract.

Background Hereditary spherocytosis (HS) is a common inherited red blood cell membrane disorder characterized by an abnormal increase of spherocytes in peripheral blood. SPTB gene mutation is one of the most common causes of HS; however, few cases of HS resulting from SPTB mutation in the Chinese population have been reported so far. Case presentation A 3-year-old Chinese girl presented to Qingdao Women and Children’s Hospital, Qingdao University, with atrial septal defect (ASD). Meanwhile, she was clinically diagnosed with HS. Whole genome sequencing (WGS) was performed for the proband and her parents for genetic molecular analysis. A novel SPTB mutation (c.1756delG) was detected by WGS and confirmed by Sanger sequencing in the proband. This mutation results in a frameshift with a premature termination codon in exon 12, leading to a nonsense mutation (p.Ala586Profs*7). Her parents had no similar symptoms, and blood routine and serum biochemical tests showed no significant abnormalities. The patient’s mother did not know of any relatives with HS-like symptoms. Percutaneous transcatheter closure was successfully performed for treating the ASD. Conclusion In this study, we identified a novel SPTB frameshift mutation in a Chinese girl with HS. This finding would expand the spectrum of SPTB mutations, provide a valuable insight into the genotyping of HS in the Chinese population, and contribute to the clinical management and genetic counseling in HS.

DCBLD2 encodes discodin, CUB and LCCL domain-containing protein 2, a type-I transmembrane receptor that is involved in intracellular receptor signalling pathways and the regulation of cell growth. In this report, we describe a 5-year-old female who presented severe clinical features, including restrictive cardiomyopathy, developmental delay, spasticity and dysmorphic features. Trio-whole-exome sequencing and segregation analysis were performed to identify the genetic cause of the disease within the family. A novel homozygous nonsense variant in the DCBLD2 gene (c.80G > A, p.W27*) was identified as the most likely cause of the patient’s phenotype. This nonsense variant falls in the extracellular N-terminus of DCBLD2 and thus might affect proper protein function of the transmembrane receptor. A number of in vitro investigations were performed on the proband’s skin fibroblasts compared to normal fibroblasts, which allowed a comprehensive assessment resulting in the functional characterization of the identified DCBLD2 nonsense variant in different cellular processes. Our data propose a significant association between the identified variant and the observed reduction in cell proliferation, cell cycle progression, intracellular ROS, and Ca2 + levels, which would likely explain the phenotypic presentation of the patient as associated with lethal restrictive cardiomyopathy.

Background We investigated pathogenic DYRK1B variants causative of abdominal obesity-metabolic syndrome 3 (AOMS3) in a group of patients originally diagnosed with type 2 diabetes. All DYRK1B exons were analyzed in a sample of 509 unrelated adults with type 2 diabetes and 459 controls, all belonging to the DMS1 SIGMA-cohort (ExAC). We performed in silico analysis on missense variants using Variant Effect Predictor software. To evaluate co-segregation, predicted pathogenic variants were genotyped in other family members. We performed molecular dynamics analysis for the co-segregating variants. Results After filtering, Mendelian genotypes were confirmed in two probands bearing two novel variants, p.Arg252His and p.Lys68Gln. Both variants co-segregated with the AOMS3 phenotype in classic dominant autosomal inheritance with full penetrance. In silico analysis revealed impairment of the DYRK1B protein function by both variants. For the first time, we describe age-dependent variable expressivity of this entity, with central obesity and insulin resistance apparent in childhood; morbid obesity, severe hypertriglyceridemia, and labile type 2 diabetes appearing before 40 years of age; and hypertension emerging in the fifth decade of life. We also report the two youngest individuals suffering from AOMS3. Conclusions Monogenic forms of metabolic diseases could be misdiagnosed and should be suspected in families with several affected members and early-onset metabolic phenotypes that are difficult to control. Early diagnostic strategies and medical interventions, even before symptoms or complications appear, could be useful.

BackgroundHypohidrotic Ectodermal Dysplasia (HED) is a genetic disorder which affects structures of ectodermal origin. X-linked hypohidrotic ectodermal dysplasia (XLHED) is the most common form of disease. XLHED is characterized by hypotrichosis, hypohydrosis and hypodontia. The cardinal features of classic HED become obvious during childhood.Identification of a hemizygous EDA pathogenic variant in an affected male confirms the diagnosis.Case presentationWe report on a male newborn with the main clinical characteristics of the X-linked HED including hypotrichosis, hypodontia and hypohidrosis. Gene panel sequencing identified a new hemizygous missense variant of uncertain significance (VUS) c.1142G > C (p.Gly381Ala) in the EDA gene, located on the X chromosome and inherited from the healthy mother.ConclusionDespite the potential functional impact of VUS remains uncharacterized, our goal is to evaluate the clinical potential consequences of missense VUS on EDA gene. Even if the proband’s phenotype is characteristic for classic HED, further reports of patients with same clinical phenotype and the same genomic variant are needed to consider this novel VUS as responsible for the development of HED.

Purpose ClinGen provides gene-specific guidance for interpretation of sequence variants in MYH7. We assessed laboratory and clinical impact of reclassification by the American College of Medical Genetics and Genomics-Association for Molecular Pathology (ACMG-AMP) and ClinGen recommendations in 43 MYH7 variants reported by a diagnostic laboratory between 2013 and 2017. Methods Fifty-two proband reports containing MYH7 variants were reinterpreted by original ACMG-AMP and ClinGen guidelines. Evidence items were compared across schemes and reasons for classification differences recorded. Laboratory impact was assessed by number of recommended report reissues, and reclassifications coded as clinically "actionable" or "equivalent." Available pedigrees were reviewed to describe projected cascade impact. Results ClinGen produced a higher proportion of diagnostic classifications (65% of variants) compared with ACMG-AMP (54%) and fewer variants of uncertain significance (30% versus 42%). ClinGen classification resulted in actionable changes in 18% of variants with equal upgrades and downgrades from original report. ClinGen's revisions to PM1 and PS4 contributed to classification differences in 21% and 19% of variants respectively. Each classification change per proband report impacted, on average, 3.1 cascade reports with a further 6.3 first- and second-degree relatives potentially available for genotyping per family. Conclusion ClinGen's gene-specific criteria provide expert-informed guidance for interpretation of MYH7 sequence variants. Periodic re-evaluation improves diagnostic confidence and should be considered by clinical and laboratory teams.

Background Dozens of genes are involved in 46, XY differences in sex development (DSD). Notably, about 3/4 of patients cannot make a clear etiology diagnosis and single gene variant identified cannot fully explain the clinical heterogeneity of 46, XY DSD. Materials and methods We conducted a systematic clinical analysis of a 46, XY DSD patient, and applied whole-exome sequencing for the genetic analysis of this pedigree. The identified variants were analyzed by bioinformatic analysis and in vitro studies were performed in human embryonic kidney 293T (HEK-293T) cells which were transiently transfected with wild type or variant NR5A1 and MAP3K1 plasmid. Furthermore, protein production of SRY-box transcription factor 9 (SOX9) was analyzed in cell lysates. Results A novel NR5A1 variant (c.929A > C, p. His310Pro) and a rare MAP3K1 variant (c.2282T > C, p. Ile761Thr) were identified in the proband, whereas the proband's mother and sister who only carry rare MAP3K1 variant have remained phenotypically healthy to the present. These two variants were predicted to be pathogenic by bioinformatic analysis. In vitro, NR5A1 variant decreased the SOX9 production by 82.11% compared to wild type NR5A1, while MAP3K1 variant had little effect on the SOX9 production compared to wild type MAP3K1. Compared to wild type NR5A1 transfection, the SOX9 production of cells transfected with both wild type plasmids decreased by about 17.40%. Compared to variant NR5A1 transfection, the SOX9 production of cells transfected with both variant plasmids increased by the 36.64%. Conclusions Our findings suggested the novel compound variants of NR5A1 and MAP3K1 can alter the expression of SOX9 and ultimately lead to abnormality of sex development.

Purpose This study aims to identify genetic causes of female infertility associated with recurrent failure of assisted reproductive technology (ART) characterized by embryonic developmental arrest. Methods We recruited infertile patients from two consanguineous families from the Reproductive Medicine Center of Guizhou Provincial People’s Hospital. Peripheral blood was collected for genomic DNA extraction. Two affected individuals and their family members were performed with whole-exome sequencing and Sanger validation in order to identify possible causative genes. For further analyzing the effect of splicing mutation on mRNA integrity in vivo, TLE6 cDNA from the peripheral blood lymphocyte of the affected individual was sequenced. In addition, the possible impact of the pathogenic mutation on the structure and function of the protein were also assessed. Results Two novel homozygous mutations in the peptidylarginine deiminase type VI (PADI6) and the transducin-like enhancer of split 6 (TLE6) genes were identified in the two families. One patient carried the frameshift deletion mutation c.831_832del:p.S278Pfs*59 of the PADI6 gene and the other patient carried the splicing mutation c.1245-2 A>G of the TLE6 gene. The analysis of the mRNA from the proband’s peripheral blood leukocytes confirmed aberrant splicing. Conclusions Our findings expand the mutational spectrum of PADI6 and TLE6 associated with embryonic developmental arrest and deepen our understanding of the genetic causes of infertility with recurrent ART failure.

Fear of cancer recurrence/occurrence (FCR/O) is prevalent and associated with poorer psychological outcomes but can also motivate individuals to pursue genomic information about cancer risk. Guided by Protection Motivation Theory, this study investigated FCR/O prevalence and associated factors among probands previously diagnosed with a cancer of likely heritable origin, and their relatives, who had agreed to have germline genome sequencing. Three hundred and forty-eight probands and 167 relatives completed the Concerns about Recurrence Questionnaire (adapted for occurrence for some relatives) within 1 month of agreeing to undertake genome sequencing. Linear regressions investigated demographic, disease, attitude and behavioral associations with FCR/O. Probands demonstrated greater FCR compared to relatives. In probands, greater FCR was associated with being female, non-English speaking at home, less time since diagnosis, greater intention to change behavior if gene variant found, lower perceived ability to cope with results, higher perceived susceptibility to having a recurrence, and more negative attitudes towards uncertainty. For relatives with cancer, greater FCR was associated with being male, greater intention to change behavior if a gene variant found, and higher perceived susceptibility to recurrence. In relatives without cancer, greater FCO was associated with not having had genetic testing prior to this study, lower perceived ability to cope with results, and higher perceived susceptibility to developing cancer. Current findings on FCR/O prevalence and associated demographic and attitudinal variables in those who pursue genomic risk information might be used to target interventions that can prevent adverse psychological outcomes in vulnerable patients.

Purpose Data regarding the clinical management and follow-up of pancreatic neuroendocrine tumors (PanNETs) associated with Von Hippel–Lindau (VHL) syndrome are limited. This study aimed to assess clinical presentation, genotype–phenotype correlations, treatment and prognosis of PanNETs in a series of VHL syndrome patients. Methods Retrospective analysis of data of patients observed between 2005 and 2020. Results Seventeen patients, including 12 probands and 5 relatives (mean age 30.8 ± 18.4; 7 males), were recruited. PanNETs were found in 13/17 patients (77.5%) at a median age of 37 years: 4/13 (30.7%) at the time of VHL diagnosis and 9 (69.3%) during follow up. Six (46.1%) PanNET patients underwent surgery, whereas seven were conservatively treated (mean tumor diameter: 40 ± 10.9 vs. 15 ± 5.3 mm respectively). Four patients (30.7%) had lymph node metastases and a mean tumor diameter significantly larger than the nonmetastatic PanNETs (44.2 ± 9.3 vs. 17.4 ± 7 mm, p = 0.00049, respectively). Five (83.3%) operated patients had stable disease after a median follow up of 3 years whereas one patient showed liver metastases. Six (85.7%) non-resected PanNETs were stable after a median follow-up of 2 years, whereas one patient developed a new small PanNET and a slight increase in diameter of a pre-existing PanNET. No correlation was found between the type of germline mutation and malignant behavior of PanNETs. Conclusions PanNETs are a common disease of the VHL syndrome and can be the presenting feature. Tumor size rather than genetic mutation is a prognostic factor of malignancy.

TRIO is a Dbl family guanine nucleotide exchange factor (GEF) and an important regulator of neuronal development. Most truncating and missense variants affecting the Dbl homology domain of TRIO are associated with a neurodevelopmental disorder with microcephaly (MIM617061). Recently, de novo missense variants affecting the spectrin repeat region of TRIO were associated with a novel phenotype comprising severe developmental delay and macrocephaly (MIM618825). Here, we provide more evidence on this new TRIO-associated phenotype by reporting two severely affected probands with de novo missense variants in TRIO affecting the spectrin repeat region upstream of the typically affected GEF1 domain of the protein.

Although the full aetiology of autism spectrum disorder (ASD) is unknown, familial and twin studies demonstrate high heritability of 60–90%, indicating a predominant role of genetics in the development of the disorder. The genetic architecture of ASD consists of a complex array of rare and common variants of all classes of genetic variation usually acting additively to augment individual risk. The relative contribution of heredity in ASD persists despite selective pressures against the classic autistic phenotype; a phenomenon thought to be explained, in part, by the incidence of spontaneous (or de novo) mutations. Notably, environmental exposures attributed as salient risk factors for ASD may play a causal role in the emergence of deleterious de novo variations, with several ASD-associated agents having significant mutagenic potential. To explore this hypothesis, this review article assesses published epidemiological data with evidence derived from assays of mutagenicity, both in vivo and in vitro, to determine the likely role such agents may play in augmenting the genetic liability in ASD. Broadly, these exposures were observed to elicit genomic alterations through one or a combination of: (1) direct interaction with genetic material; (2) impaired DNA repair; or (3) oxidative DNA damage. However, the direct contribution of these factors to the ASD phenotype cannot be determined without further analysis. The development of comprehensive prospective birth cohorts in combination with genome sequencing is essential to forming a causal, mechanistic account of de novo mutations in ASD that links exposure, genotypic alterations, and phenotypic consequences.

Gelsolin (GSN) variants have been implicated in amyloidosis of the Finnish type. This case series reports a novel GSN:c.1477T>C,p.(Trp493Arg) variant in a family with ocular and systemic features consistent with Finnish Amyloidosis. Exome sequencing performed on affected individuals from two families manifesting cutis laxa and polymorphic corneal stromal opacities demonstrated the classic GSN:c.654G>A,p.Asp214Asn variant in single affected individual from one family, and a previously undocumented GSN:c.1477T>C variant in three affected first-degree relatives from a separate family. Immunohistochemical studies on corneal tissue from a proband with the c.1477T>C variant identified gelsolin protein within histologically defined corneal amyloid deposits. This study reports a novel association between the predicted pathogenic GSN:c.1477T>C variant and amyloidosis of the Finnish type, and is the first to provide functional evidence of a pathological GSN variant at a locus distant to the critical G2 calcium-binding region, resulting in the phenotype of amyloidosis of the Finnish type.

Gitelman syndrome (GS) is an autosomal recessive inherited salt-losing renal tubular disease, which is caused by a pathogenic mutation of SLC12A3 encoding thiazide-sensitive Na-Cl cotransporter, which leads to disturbance of sodium and chlorine reabsorption in renal distal convoluted tubules, resulting in phenotypes such as hypovolemia, renin angiotensin aldosterone system (RAAS) activation, hypokalemia, and metabolic alkalosis. In this study, two GS families with proteinuria or Hashimoto’s thyroiditis were analyzed for genetic-phenotypic association. Sanger sequencing revealed that two probands carried SLC12A3 compound heterozygous mutations, and proband A carried two pathogenic mutations: missense mutation Arg83Gln, splicing mutation, or frameshift mutation NC_000016.10:g.56872655_56872667 (gcggacatttttg>accgaaaatttt) in exon 8. Proband B carries two missense mutations: novel Asp839Val and Arg904Gln. Both probands manifested hypokalemia, hypomagnesemia, hypocalcinuria, metabolic alkalosis, and RAAS activation; in addition, the proband A exhibited decreased urinary chloride, phosphorus, and increased magnesium ions excretion, complicated with Hashimoto’s Thyroiditis, while the proband B exhibited enhanced urine sodium excretion and proteinuria. The older sister of proband B with GS also had Hashimoto’s thyroiditis. Electron microscopy revealed swelling and vacuolar degeneration of glomerular epithelial cells, diffuse proliferation of mesangial cells and matrix, accompanied by a small amount of low-density electron-dense deposition, and segmental fusion of epithelial cell foot processes in proband B. Light microscopy showed mild mesangial hyperplasia in the focal segment of the glomerulus, hyperplasia, and hypertrophy of juxtaglomerular apparatus cells, mild renal tubulointerstitial lesions, and one glomerular sclerosis. So, long-term hypokalemia of GS can cause kidney damage and may also be susceptible to thyroid disease.

Background Cone dystrophy with supernormal rod response (CDSRR) is a rare inherited retinal degeneration. A patient superimposed with medical conditions requiring use of hydroxychloroquine (HCQ) may obscure accurate diagnosis of CDSRR. Herein, we report a referral case for HCQ retinopathy screening. Comprehensive ophthalmic examinations, however, guided the diagnosis of CDSRR from a novel mutation in potassium voltage-gated channel modifier subfamily V member 2 (KCNV2) gene. Materials and methods Comprehensive ophthalmic examinations were evaluated for two patients whose parents are first cousins. Direct sanger sequencing of KCNV2 was applied to confirm the mutation. Results A 38-year-old male proband was referred for HCQ retinopathy screening after taking HCQ for systemic lupus erythematosus (SLE). Fundus examination showed bull's eye pattern, and photoreceptor loss in the foveal region of both eyes was noted on spectral domain-optical coherence tomography (SD-OCT). The full-field electroretinography (ffERG) revealed a disproportionate increase in scotopic maximal response with implicit time delay, as well as universal cone dysfunction. Proband's 24-year-old sister had similar ffERG pattern in both eyes. Direct sanger sequencing of KCNV2 gene revealed a novel homozygous mutation c.280_281 insG (p.Ala94GlyfsTer278), confirming a diagnosis of CDSRR. Conclusions We report a novel KCNV2 mutation in a consanguineous family. The unique ffERG features of CDSRR are pathognomonic and thus crucial in guiding clinicians toward genetic testing of the KCNV2 gene. Altogether, multimodal imaging, ffERG, and detailed history taking are important diagnostic tools for differentiating between acquired and inherited retinal disorders.

Prostate cancer (PCa) is one of the most common malignant tumor in men. Significant advances have been made in the early detection and treatment of localized PCa, but metastatic castration-resistant PCa (mCRPC) remains one of the most challenging problems to treat in oncology. To improve treatment outcomes for patients at this stage of the disease, it is necessary to develop personalized therapy options based on the definition of biological predictors. In mCRPC, mutations in DNA repair genes are detected in ~23 % of patients with mCRPC. Detection of these mutations in patients with PCa has important clinical relevance. PCa with mutations in DNA repair genes may be sensitive to poly(ADP-ribose)-polymerase (PARP) inhibitors. Several studies II and III phase have demonstrated the effectiveness of PARP inhibitors with a high objective response rate in the treatment of mCRPC in patients with mutations in the DNA repair genes, which is definitely a more personalized approach to treatment. Identification of hereditary mutations in DNA repair genes is an important prognostic factor for the proband's relatives (for both men and women), which can later be used for genetic counseling of patients and the application of strategies to reduce the risk of malignant diseases.

Objectives To identify the genetic cause of one Chinese family with hypoplastic amelogenesis imperfecta (AI) and explore the relationship between genotype and its phenotype. Material and methods One Chinese family with generalized hypoplastic AI was recruited. One deciduous tooth from the proband was subjected to scanning electron microscopy. Whole-exome sequencing was performed and identified mutation was confirmed by Sanger sequencing. Bioinformatics studies were further conducted to analyze potential deleterious effects of the mutation. Results The proband presented a typical hypoplastic AI phenotype whose teeth in deciduous and permanent dentitions showed thin, yellow, and hard enamel surface. The affected enamel in deciduous tooth showed irregular, broken, and collapsing enamel rods with borders of the enamel prisms undulated and structural shapes of prisms irregular. A novel homozygous nonsense mutation in the last exon of the enamelin (ENAM) gene (NM_031889.3; c.2078C>G) was identified in the proband, which was predicted to produce a highly truncated protein (NP_114095.2; p.(Ser693*)). This mutation was also identified in the proband's parents in heterozygous form. Surprisingly, the clinical phenotype of the heterozygous parents varied from a lack of penetrance to mild enamel defects. Additional bioinformatics studies demonstrated that the detected mutation could change the 3D structure of the ENAM protein and severely damaged the function of ENAM. Conclusion The novel homozygous ENAM mutation resulted in hypoplastic AI in the present study. Our results provide new genetic evidence that mutations involved in ENAM contribute to hypoplastic AI.

Hb A2 levels are usually high in carriers of β-thalassemia (β-thal). These levels also provide a sensitive marker for the identification of hemoglobin (Hb) variants. In this study, we aimed to examine two patients from two Chinese families who showed elevated Hb A2 levels but did not show any signs of β-thal. The HBB variants were analyzed using direct sequencing of HBB and in silico prediction analysis. Moreover, the family's genetic history was investigated. We examined two probands from different Chinese families with elevated Hb A2 levels who were not afflicted with β-thal, although several nucleotide changes were found at codon 81 (CTC>CTA) (HBB: c.246C>A) in Family 1 and a compound heterozygosity for codon 40 (AGG>AAG) (HBB: c.122G>A) and IVS-II-478 (C>A) (HBB: c.316-373C>A) in Family 2. After investigating the genetic history of both families including the β-thal aspect, we found that these mutations were not responsible for the elevated Hb A2 levels. It is rarely reported that high Hb A2 level is not indicative of β-thal. In contrast, low or normal Hb A2 level is always found with β-thal due to other molecular defects that mask their β-thal genotype. Our results highlight the importance of considering the genetic factors related and unrelated to β-thal to improve the accuracy of future genetic counseling.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease characterized by the development of renal cysts and progression to renal failure. Preimplantation genetic testing-monogenic disease (PGT-M) is an alternative option to obtain healthy babies. However, de novo PKD1 mutation of one of the spouses or the absence of a positive family history poses a serious challenge to PGT-M. Here, we described a comprehensive strategy which includes preimplantation genetic testing for aneuploidies (PGT-A) study and monogenic diagnosis study for ADPKD patients bearing de novo mutations. The innovation of our strategy is to use the gamete (polar body or single sperm) as proband for single-nucleotide polymorphism (SNP) linkage analysis to detect an embryo’s carrier status. Nine ADPKD couples with either de novo mutation or without a positive family history were recruited and a total of 34 embryos from 13 PGT-M cycles were examined. Within these nine couples, two successfully delivered healthy babies had their genetic status confirmed by amniocentesis. This study provides a creative approach for embryo diagnosis of patients with de novo mutations or patients who lack essential family members for linkage analysis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10815-021-02188-z.

Familial hypercholesterolemia (FH) is a common genetic disease that is estimated to affect at least 15 million people in the Asia Pacific region. Affected individuals are at significantly increased risk of premature atherosclerotic cardiovascular disease. A literature review was undertaken to provide an overview of the epidemiology, diagnosis, and management of FH across the region. Currently, epidemiological data relating to FH are lacking across the Asia Pacific. Of the 15 countries and regions considered, locally conducted studies to determine FH prevalence were only identified for Australia, China, India, and Japan. Although practically all national clinical guidelines for dyslipidemia include some commentary on FH, specific guidelines on the management of FH are available for only one third of the countries and regions evaluated. Estimates of current FH diagnosis rates suggest that most affected individuals remain undiagnosed and untreated. Although innovative medications such as proprotein convertase subtilisin/kexin type 9 inhibitors have been approved and are available in most countries and regions considered, they are currently reimbursed in only one quarter. Despite these shortcomings, there is cause for optimism. Early experience with cascade screening in Hong Kong, India, and Vietnam has proven an effective means of identifying family members of probands, as has a reverse screening of family members of children with FH in China. FH registries are gaining momentum across the region, with registries now established in almost half of the countries and regions evaluated. This review concludes with a Call to Action on FH for Asia Pacific to engage healthcare professionals, improve public awareness, and form national FH alliances, comprising all relevant healthcare professional organizations, as a platform to expedite national quality improvement programs in the management of FH.

Objectives This study aimed to perform an external validation of the value of right ventricular (RV) deformation patterns and RV mechanical dispersion in patients with arrhythmogenic cardiomyopathy (AC). Secondly, this study assessed the association of these parameters with life-threatening ventricular arrhythmia (VA). Background Subtle RV dysfunction assessed by echocardiographic deformation imaging is valuable in AC diagnosis and risk prediction. Two different methods have emerged, the RV deformation pattern recognition and RV mechanical dispersion, but these have neither been externally validated nor compared. Methods We analyzed AC probands and mutation-positive family members, matched from 2 large European referral centers. We performed speckle tracking echocardiography, whereby we classified the subtricuspid deformation patterns from normal to abnormal and assessed RV mechanical dispersion from 6 segments. We defined VA as sustained ventricular tachycardia, appropriate implantable cardioverter-defibrillator therapy, or aborted cardiac arrest. Results We included 160 subjects, 80 from each center (43% proband, 55% women, age 41 ± 17 years). VA had occurred in 47 (29%) subjects. In both cohorts, patients with a history of VA showed abnormal deformation patterns (96% and 100%) and had greater RV mechanical dispersion (53 ± 30 ms vs. 30 ± 21 ms; p Conclusions We externally validated 2 RV dysfunction parameters in AC. Adding RV mechanical dispersion to RV deformation patterns significantly improved the association with life-threatening VA, indicating incremental value.

Background ARVC is a rare genetic-related disease characterized by fibrous fat replacement in the ventricular myocardium, caused by mutations in genes encoding for the desmosomal proteins, such as the desmoglein-2 gene (DSG2). It is reported in the literature that other genetic factors may play a role in disease penetrance. Herein, we report a Chinese proband with ARVC, which was probably caused by DSG2 p.Val149Ile mutation as genetic background when carrying heterozygous PRRT2 p.Arg217ProfsTer8 mutation. Case presentation A 17-year-old male with a history of paroxysmal kinesigenic dyskinesia (PKD) presented to the hospital for syncope induced by ventricular tachycardia. According to relevant clinical data and the diagnostic criteria of ARVC, a precise positive diagnosis of ARVC was finally made. Gene testing revealed that the patient carried a DSG2 heterozygous missense mutation (NM_001943: exon5: c.445G>A, p.Val149Ile) as well as frameshift mutation of PRRT2 (NM_001256442: exon2: p. Arg217Profs Ter8). Conclusion This is the first time to report a Chinese proband with ARVC and a history of PKD carrying both DSG2 p. val149ile mutation and PRRT2 p. Arg217ProfsTer8 mutation, which can provide a new direction for gene screening of patients with ARVC and further supplements for its diagnostic criteria.

Purpose: To explore disease-causing gene mutations of epilepsy with febrile seizures plus (EFS+) in Southern Chinese Han population. Methods: Blood samples and clinical data were collected from 49 Southern Han Chinese patients with EFS+. Gene screening was performed using whole-exome sequencing and panel sequencing for 485 epilepsy-related genes. The pathogenicity of variants was evaluated based on ACMG scoring and assessment of clinical concordance. Results: We identified 10 putatively causative sodium channel gene variants in 49 patients with EFS+, including 8 variants in SCN1A (R500Q appeared twice), one in SCN3A and one in SCN9A. All these missense mutations were inherited from maternal or paternal and were evaluated to be of uncertain significance according to ACMG. The clinical features of patients were in concordance with the EFS+ phenotype of the mutated SCN1A, SCN3A and SCN9A gene. The clinical phenotypes of 11 probands with these gene variants included febrile seizures plus (FS+, n=7), Dravet Syndrome (n=3), FS+ with focal seizures (n=1). Three probands with SCN1A variants (R500Q located in the non-voltage areas, or G1711D in the pore-forming domain) developed severe Dravet syndrome. The affected individuals with the other 6 SCN1A variants located outside the pore-forming domain showed mild phenotypes. Novel SCN3A variant ((D1688Y) and SCN9A variant (R185H) were identified in two probands respectively and both of the probands had FS+. Conclusion: The SCN1A, SCN3A, and SCN9A gene mutations might be a pathogenic cause of EFS+ in Southern Chinese Han population.

Microphthalmia, coloboma, and aniridia are congenital ocular phenotypes with a strong genetic component but often unknown cause. We present a likely causative novel variant in MAB21L1, c.152G>T p.(Arg51Leu), in two family members with microphthalmia and aniridia, as well as novel or rare compound heterozygous variants of uncertain significance, c.184C>T p.(Arg62Cys)/c.‐68T>C, and c.658G>C p.(Gly220Arg)/c.*529A>G, in two additional probands with microphthalmia, coloboma and/or cataracts. All variants were predicted as damaging by in silico programs. In vitro studies of coding variants revealed normal subcellular localization but variable stability for the corresponding mutant proteins. In vivo complementation assays using the zebrafish mab21l2 Q48Sfs*5 loss‐of‐function line demonstrated that though overexpression of wild‐type MAB21L1 messenger RNA (mRNA) compensated for the loss of mab21l2, none of the coding variant mRNAs produced a statistically significant rescue, with p.(Arg51Leu) showing the highest degree of functional deficiency. Dominant variants in a close homolog of MAB21L1, MAB21L2, have been associated with microphthalmia and/or coloboma and repeatedly involved the same Arg51 residue, further supporting its pathogenicity. The possible role of p.(Arg62Cys) and p.(Gly220Arg) in microphthalmia is similarly supported by the observed functional defects, with or without an additional impact from noncoding MAB21L1 variants identified in each patient. This study suggests a broader spectrum of MAB21L1‐associated disease., MAB21L1 alleles in microphthalmia and aniridia.

International audience; Pathogenic variants in the PSTPIP1 gene cause pyogenic sterile arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome. They were also identified in a broad spectrum of phenotypes. As their interpretation is sometimes challenging, we discuss the genotype-phenotype association in PSTPIP1-associated autoinflammatory diseases (PAIDs) in light of a recent consensus classification of variant pathogenicity. Only 7 of 39 (18%) of the PSTPIP1 variants found in all reported cases and our national reference center (161 patients [114 probands]) were pathogenic. They were clearly associated with PAPA and PSTPIP1-associated myeloid-related proteinemia inflammatory syndrome (PAMI), reflecting a variable clinical expression of PAIDs.

An 11-year-old Korean boy presented with short stature, hip dysplasia, radial head dislocation, carpal coalition, genu valgum, and fixed patellar dislocation and was clinically diagnosed with Steel syndrome. Scrutinizing the trio whole-exome sequencing data revealed novel compound heterozygous mutations of COL27A1 (c.[4229_4233dup]; [3718_5436del], p.[Gly1412Argfs*157];[Gly1240_Lys1812del]) in the proband, which were inherited from heterozygous parents. The maternal mutation was a large deletion encompassing exons 38–60, which was challenging to detect.

PURPOSE To present the scope of prenatal diagnosis and early treatment of patients with clinically heterogeneous phenotypic retinal dysplasia associated with NDP gene variants. METHODS Retrospective. Review of electronic medical records. RESULTS Twenty-nine-year-old woman known to carry a NDP gene variant presented to the eye clinic for consultation and risk assessment at her second pregnancy. Her 11-year-old son had bilateral retinal detachment, despite surgical treatment. The family declined prenatal testing. The patient was born full term, was examined, and underwent genetic testing after birth. He was found to have bilateral retinal avascular periphery abnormalities and preretinal hemorrhages on the left eye. The patient received bilateral laser treatment at 2 months of age. He was found to be doing well at 16 months after treatment with adequate visual acuity and flat maculae. The asymptomatic mother and maternal grandfather of the proband were found to have retinal periphery abnormalities with unremarkable posterior pole and excellent visual acuity. CONCLUSION NDP gene variants associated with X-linked familial exudative vitreoretinopathy phenotype benefit from early treatment. Providers who take care of these patients need to monitor closely the pregnancy and delivery of a male child born to a female carrier to offer appropriate and timely treatment.

Spinal muscular atrophy with congenital bone fractures 2 (SMABF2), a type of arthrogryposis multiplex congenita (AMC), is characterized by congenital joint contractures, prenatal fractures of long bones, and respiratory distress and results from biallelic variants in ASCC1. Here, we describe an infant with severe, diffuse hypotonia, congenital contractures, and pulmonary hypoplasia characteristic of SMABF2, with the unique features of cleft palate, small spleen, transverse liver, and pulmonary thromboemboli with chondroid appearance. This infant also had impaired coagulation with diffuse petechiae and ecchymoses which has only been reported in one other infant with AMC. Using trio whole genome sequencing, our proband was identified to have biallelic variants in ASCC1. Using deep next generation sequencing of parental cDNA, we characterized alteration of splicing encoded by the novel, maternally inherited ASCC1 variant (c.297-8 T > G) which provides a mechanism for functional pathogenicity. The paternally inherited ASCC1 variant is a rare nonsense variant (c.466C > T; p.Arg156*) that has been previously identified in one other infant with AMC. This report extends the phenotypic characteristics of ASCC1-associated AMC (SMABF2) and describes a novel intronic variant that partially disrupts RNA splicing.

High coagulation factor VIII (FVIII) levels comprise a common risk factor for venous thromboembolism (VTE), but the underlying genetic determinants are largely unknown. We investigated the molecular bases of high FVIII levels in 2 Italian families with severe thrombophilia. The proband of the first family had a history of recurrent VTE before age 50 years, with extremely and persistently elevated FVIII antigen and activity levels (>400%) as the only thrombophilic defects. Genetic analysis revealed a 23.4-kb tandem duplication of the proximal portion of the F8 gene (promoter, exon 1, and a large part of intron 1), which cosegregated with high FVIII levels in the family and was absent in 103 normal controls. Targeted screening of 50 unrelated VTE patients with FVIII levels ≥250% identified a second thrombophilic family with the same F8 rearrangement on the same genetic background, suggesting a founder effect. Carriers of the duplication from both families showed a twofold or greater upregulation of F8 messenger RNA, consistent with the presence of open chromatin signatures and enhancer elements within the duplicated region. Testing of these sequences in a luciferase reporter assay pinpointed a 927-bp region of F8 intron 1 associated with >45-fold increased reporter activity in endothelial cells, potentially mediating the F8 transcriptional enhancement observed in carriers of the duplication. In summary, we report the first thrombophilic defect in the F8 gene (designated FVIII Padua) associated with markedly elevated FVIII levels and severe thrombophilia in 2 Italian families.