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Background: Data on dermatological manifestations of Costello syndrome (CS) remain heterogeneous and lack in validated description. Objectives: To describe the dermatological manifestations of CS; compare them with the literature findings; assess those discriminating CS from other RASopathies, including cardiofaciocutaneous syndrome (CFCS) and the main types of Noonan syndrome (NS); and test for dermatological phenotype–genotype correlations. Methods: We performed a 10‐year, large, prospective, multicentric, collaborative dermatological and genetic study. Results: Thirty‐one patients were enrolled. Hair abnormalities were ubiquitous, including wavy or curly hair and excessive eyebrows, respectively in 68% and 56%. Acral excessive skin (AES), papillomas and keratotic papules (PKP), acanthosis nigricans (AN), palmoplantar hyperkeratosis (PPHK) and 'cobblestone' papillomatous papules of the upper lip (CPPUL), were noted respectively in 84%, 61%, 65%, 55% and 32%. Excessive eyebrows, PKP, AN, CCPUL and AES best differentiated CS from CFCS and NS. Multiple melanocytic naevi (>50) may constitute a new marker of attenuated CS associated with intragenic duplication in HRAS. Oral acitretin may be highly beneficial for therapeutic management of PPHK. No significant dermatological phenotype–genotype correlation was determined between patients with and without HRAS c.34G>A (p.G12S). Conclusions and Relevance: This validated phenotypic characterization of a large number of patients with CS will allow future researchers to make a positive diagnosis, and to differentiate CS from CFCS and NS. [ABSTRACT FROM AUTHOR]

DYRK1A Syndrome (OMIM #614104) is caused by pathogenic variations in the DYRK1A gene located on 21q22. Haploinsufficiency of DYRK1A causes a syndrome with global psychomotor delay and intellectual disability. Low birth weight, growth restriction with feeding difficulties, stature insufficiency, and microcephaly are frequently reported. This study aims to create specific growth charts for individuals with DYRK1A Syndrome and identify parameters for size prognosis. Growth parameters were obtained for 92 individuals with DYRK1A Syndrome (49 males vs. 43 females). The data were obtained from pediatric records, parent reporting, and scientific literature. Growth charts for height, weight, body mass index (BMI), and occipitofrontal circumference (OFC) were generated using generalized additive models through R package gamlss. The growth curves include height, weight, and OFC measurements for patients aged 0–5 years. In accordance with the literature, the charts show that individuals are more likely to present intrauterine growth restriction with low birth weight and microcephaly. The growth is then characterized by severe microcephaly, low weight, and short stature. This study proposes growth charts for widespread use in the management of patients with DYRK1A syndrome. [ABSTRACT FROM AUTHOR]

We present the phenotype of an infant with the largest ATN1 CAG expansion reported to date (98 repeats). He presented at 4 months with developmental delay, poor eye contact, acquired microcephaly, failure to thrive. He progressively developed dystonia‐parkinsonism with paroxysmal oromandibular and limbs dyskinesia and fatal outcome at 17 months. Cerebral MRI disclosed globus pallidus T2‐WI hyperintensities and brain atrophy. Molecular analysis was performed post‐mortem following the diagnosis of dentatorubral–pallidoluysian atrophy (DRPLA) in his symptomatic father. Polyglutamine expansion defects should be considered when neurodegenerative genetic disease is suspected even in infancy and parkinsonism can be a presentation of infantile‐onset DRPLA. [ABSTRACT FROM AUTHOR]

Unique or multiple congenital facial skin polyps are features of several rare syndromes, from the most well‐known Pai syndrome (PS), to the less recognized oculoauriculofrontonasal syndrome (OAFNS), encephalocraniocutaneous lipomatosis (ECCL), or Sakoda complex (SC). We set up a research project aiming to identify the molecular bases of PS. We reviewed 27 individuals presenting with a syndromic frontonasal polyp and initially referred for PS. Based on strict clinical classification criteria, we could confirm only nine (33%) typical and two (7%) atypical PS individuals. The remaining ones were either OAFNS (11/27—41%) or presenting with an overlapping syndrome (5/27—19%). Because of the phenotypic overlap between these entities, OAFNS, ECCL, and SC can be either considered as differential diagnosis of PS or part of the same spectrum. Exome and/or genome sequencing from blood DNA in 12 patients and from affected tissue in one patient failed to identify any replication in candidate genes. Taken together, our data suggest that conventional approaches routinely utilized for the identification of molecular etiologies responsible for Mendelian disorders are inconclusive. Future studies on affected tissues and multiomics studies will thus be required in order to address either the contribution of mosaic or noncoding variation in these diseases. [ABSTRACT FROM AUTHOR]

Objectives: The antenatal phenotypic spectrum of Noonan Syndrome (NS) requires better characterization. Methods: This multicenter retrospective observational included 16 fetuses with molecularly confirmed NS admitted for fetopathological examination between 2009 and 2016. Results: Among 12 pathogenic variants (PV) in PTPN11 (80%), 5 (42%) fell between position c.179 and c.182. Ultrasound showed increased nuchal translucency (n = 13/16, 93%), increased nuchal fold after 15 weeks of gestation (n = 12/16, 75%), pleural effusions (n = 11/16, 69%), polyhydramnios (n = 9/16, 56%), hydrops (n = 7/16, 44%), cardiovascular (n = 6/16, 38%) and cerebral (n = 4/16, 25%) anomalies. Fetopathological examination found dysmorphic features in all cases, cardiovascular anomalies (n = 12/15, 80%), pulmonary hypoplasia (n = 10/15, 67%), effusions (n = 7/15, 47%) and neuropathological anomalies (n = 5/15, 33%). Hydrops was significantly (p = 0.02) more frequent in the four fetuses with RIT1, NRAS and RAF1 PV versus the 12 fetuses with PTPN11 PV. Conclusions: Increased nuchal translucency and nuchal fold is common in NS. Noonan Syndrome antenatal phenotype showed high in utero fetal death, hydrops, prenatal pleural effusion and pulmonary hypoplasia, although the inclusion of only deceased fetuses will have selected more severe phenotypes. Non‐specific cardiovascular and neurological abnormalities should be added to NS antenatal phenotype. Next generation sequencing will help detect more genotypes, clarifying the prenatal phenotype and identifying genotype‐phenotype correlations. Key points: What's already known about this topic? Noonan Syndrome (NS) is an autosomal dominant disorder with highly variable antenatal phenotype, which sometimes does not correlate with the severity of the postnatal phenotype, making counseling challenging.The ultrasound phenotype of NS is associated with increased nuchal translucency in first trimester and beyond the second trimester of pregnancy, polyhydramnios, pleural effusion, ascites, edema and cardiac and facial anomalies.These signs are frequent and non‐specific. What does this study add? This case series better characterizes fetuses carrying NS, identifying a wider phenotypic spectrum than originally reported. The antenatal phenotype includes non‐specific cardiovascular, renal and neurological abnormalities.This phenotype seems to be more severe than previously thought, with a high rate of hydrops, prenatal pleural effusion and pulmonary hypoplasia.Different genotypes have specific phenotypes, for example, hydrops was more associated to mutations in non‐PTPN11 targets. [ABSTRACT FROM AUTHOR]

Smith‐Magenis syndrome (SMS), characterized by dysmorphic features, neurodevelopmental disorder, and sleep disturbance, is due to an interstitial deletion of chromosome 17p11.2 (90%) or to point mutations in the RAI1 gene. In this retrospective cohort, we studied the clinical, cognitive, and behavioral profile of 47 European patients with SMS caused by a 17p11.2 deletion. We update the clinical and neurobehavioral profile of SMS. Intrauterine growth was normal in most patients. Prenatal anomalies were reported in 15%. 60% of our patients older than 10 years were overweight. Prevalence of heart defects (6.5% tetralogy of Fallot, 6.5% pulmonary stenosis), ophthalmological problems (89%), scoliosis (43%), or deafness (32%) were consistent with previous reports. Epilepsy was uncommon (2%). We identified a high prevalence of obstipation (45%). All patients had learning difficulties and developmental delay, but ID range was wide and 10% of patients had IQ in the normal range. Behavioral problems included temper tantrums and other difficult behaviors (84%) and night‐time awakenings (86%). Optimal care of SMS children is multidisciplinary and requires important parental involvement. In our series, half of patients were able to follow adapted schooling, but 70% of parents had to adapt their working time, illustrating the medical, social, educative, and familial impact of having a child with SMS. [ABSTRACT FROM AUTHOR]

White‐Sutton syndrome is a rare developmental disorder characterized by global developmental delay, intellectual disabilities (ID), and neurobehavioral abnormalities secondary to pathogenic pogo transposable element‐derived protein with zinc finger domain (POGZ) variants. The purpose of our study was to describe the neurocognitive phenotype of an unbiased national cohort of patients with identified POGZ pathogenic variants. This study is based on a French collaboration through the AnDDI‐Rares network, and includes 19 patients from 18 families with POGZ pathogenic variants. All clinical data and neuropsychological tests were collected from medical files. Among the 19 patients, 14 patients exhibited ID (six mild, five moderate and three severe). The five remaining patients had learning disabilities and shared a similar neurocognitive profile, including language difficulties, dysexecutive syndrome, attention disorders, slowness, and social difficulties. One patient evaluated for autism was found to have moderate autism spectrum disorder. This study reveals that the cognitive phenotype of patients with POGZ pathogenic variants can range from learning disabilities to severe ID. It highlights that pathogenic variations in the same genes can be reported in a large spectrum of neurocognitive profiles, and that children with learning disabilities could benefit from next generation sequencing techniques. [ABSTRACT FROM AUTHOR]

Objective: Osteoarthritis (OA) is the most common joint disease worldwide. The etiology of OA is varied, ranging from multifactorial to environmental to monogenic. In a condition called early‐onset OA, OA occurs at an earlier age than is typical in the general population. To our knowledge, there have been no large‐scale genetic studies of individuals with early‐onset OA. The present study was undertaken to investigate causes of monogenic OA in individuals with nonsyndromic early‐onset OA. Methods: The study probands were 45 patients with nonsyndromic early‐onset OA who were referred to our skeletal disease center by skeletal dysplasia experts between 2013 and 2019. Criteria for early‐onset OA included radiographic evidence, body mass index ≤30 kg/m2, age at onset ≤50 years, and involvement of ≥1 joint site. Molecular analysis was performed with a next‐generation sequencing panel. Results: We identified a genetic variant in 13 probands (29%); the affected gene was COL2A1 in 11, ACAN in 1, and SLC26A2 in 1. After familial segregation analysis, 20 additional individuals were identified. The mean ± SD age at onset of joint pain was 19.5 ± 3.9 years (95% confidence interval 3–47). Eighteen of 33 subjects (55%) with nonsyndromic early‐onset OA and a genetic variant had had at least 1 joint replacement (mean ± SD age at first joint replacement 41 ± 4.2 years; mean number of joint replacements 2.6 per individual), and 21 (45%) of the joint replacement surgeries were performed when the patient was <45 years old. Of the 20 patients age >40 years, 17 (85%) had had at least 1 joint replacement. Conclusion: We confirmed that COL2A1 is the main monogenic cause of nonsyndromic early‐onset OA. However, on the basis of genetic heterogeneity of early‐onset OA, we recommend next‐generation sequencing for all individuals who undergo joint replacement prior to the age of 45 years. Lifestyle recommendations for prevention should be implemented. [ABSTRACT FROM AUTHOR]

PITX1 is a homeobox transcription factor essential for hindlimb morphogenesis. Two PITX1‐related human disorders have been reported to date: PITX1 ectopic expression causes Liebenberg syndrome, characterized by malformation of upper limbs showing a "lower limb" appearance; PITX1 deletions or missense variation cause a syndromic picture including clubfoot, tibial hemimelia, and preaxial polydactyly. We report two novel PITX1 missense variants, altering PITX1 transactivation ability, in three individuals from two unrelated families showing a distinct recognizable autosomal dominant syndrome, including first branchial arch, pelvic, patellar, and male genital abnormalities. This syndrome shows striking similarities with the Pitx1−/− mouse model. A partial phenotypic overlap is also observed with Ischiocoxopodopatellar syndrome caused by TBX4 haploinsufficiency, and with the phenotypic spectrum caused by SOX9 anomalies, both genes being PITX1 downstream targets. Our study findings expand the spectrum of PITX1‐related disorders and suggest a common pattern of developmental abnormalities in disorders of the PITX1–TBX4–SOX9 signaling pathway. [ABSTRACT FROM AUTHOR]

Pycnodysostosis is a lysosomal autosomal recessive skeletal dysplasia characterized by osteosclerosis, short stature, acro‐osteolysis, facial features and an increased risk of fractures. The clinical heterogeneity of the disease and its rarity make it difficult to provide patients an accurate prognosis, as well as appropriate care and follow‐up. French physicians from the OSCAR network have been asked to fill out questionnaires collecting molecular and clinical data for 27 patients issued from 17 unrelated families. All patients showed short stature (mean = −3.5 SD) which was more severe in females (P = .006). The mean fracture rate was moderate (0.21 per year), with four fractures in total average. About 75% underwent at least one surgery, with an average number of 2.1 interventions per patient. About 50% required non‐invasive assisted ventilation due to sleep apnea (67%). About 29% showed psychomotor difficulties and 33% needed a school assistant or adapted schooling. No patient had any psychological evaluation or follow‐up. Molecular data were available for 14 families. Growth hormone administration was efficient on linear growth in 40% of cases. We propose several axis of management, such as systematic cerebral MRI for Chiari malformation screening at diagnosis and regular psychological follow‐up. [ABSTRACT FROM AUTHOR]

Treacher Collins syndrome (TCS) is a frequent cause of mandibulofacial dysostosis. To date, TCS‐causing mutations in three genes, namely TCOF1, POLR1D, and POLR1C have been identified. TCS is usually inherited in an autosomal dominant manner, with a high clinical variability and no phenotype–genotype correlation. Up‐to now, five families have been reported with an autosomal recessive mode of inheritance due to mutations in POLR1D or POLR1C. We report here a new family with two sisters affected by mild TCS carrying compound POLR1C heterozygous mutations, and review the literature on mild forms of TCS, autosomal recessive inheritance in this syndrome and POLR1C mutations. [ABSTRACT FROM AUTHOR]

Polymorphisms have been identified in the Xq28 locus as risk loci for rheumatoid arthritis (RA). Here, we investigated the association between three polymorphisms in the Xq28 region containing TMEM187 and IRAK1 (rs13397, rs1059703, and rs1059702) in two unstudied populations: Tunisian and French. The rs13397 G and rs1059703 T major alleles were significantly increased in RA patients (n = 408) compared with age-matched controls (n = 471) in both Tunisian and French women. These results were confirmed by a meta-analysis replication study including two independent Greek and Korean cohorts. The rs1059702 C major allele was significantly associated with RA, only with French women. In the French population, the GTC haplotype displayed a protective effect against RA, while the ATC, GCC, and GTT haplotypes conferred significant risk for RA. No association for these haplotypes was found in the Tunisian population. Our results replicated for the first time the association of the three Xq28 polymorphisms with RA risk in Tunisian and French populations and suggested that RA susceptibility is associated with TMEM187-IRAK1 polymorphisms in women. Our data further support the involvement of X chromosome in RA susceptibility and evidence ethnicities differences that might be explained by differences in the frequencies of SE HLA-DRB1 alleles between both populations. [ABSTRACT FROM AUTHOR]

The oculoauriculofrontonasal syndrome (OAFNS) is a rare disorder characterized by the association of frontonasal dysplasia (widely spaced eyes, facial cleft, and nose abnormalities) and oculo‐auriculo‐vertebral spectrum (OAVS)‐associated features, such as preauricular ear tags, ear dysplasia, mandibular asymmetry, epibulbar dermoids, eyelid coloboma, and costovertebral anomalies. The etiology is unknown so far. This work aimed to identify molecular bases for the OAFNS. Among a cohort of 130 patients with frontonasal dysplasia, accurate phenotyping identified 18 individuals with OAFNS. We describe their clinical spectrum, including the report of new features (micro/anophtalmia, cataract, thyroid agenesis, polymicrogyria, olfactory bulb hypoplasia, and mandibular cleft), and emphasize the high frequency of nasal polyps in OAFNS (56%). We report the negative results of ALX1, ALX3, and ALX4 genes sequencing and next‐generation sequencing strategy performed on blood‐derived DNA from respectively, four and four individuals. Exome sequencing was performed in four individuals, genome sequencing in one patient with negative exome sequencing result. Based on the data from this series and the literature, diverse hypotheses can be raised regarding the etiology of OAFNS: mosaic mutation, epigenetic anomaly, oligogenism, or nongenetic cause. In conclusion, this series represents further clinical delineation work of the rare OAFNS, and paves the way toward the identification of the causing mechanism. [ABSTRACT FROM AUTHOR]

Background: General practitioners (GPs) have an increasing role in referring patients with putative mutation in BRCA1/2 genes for genetics consultation and for long‐term follow‐up of mutation carriers. Methods: We compared the expectations of the GPs' role according to BRCA1/2 mutation carriers and to GPs themselves. Results: Overall, 38% (58/152) of eligible GPs and 70% (176/252) of eligible patients were surveyed. Although 81% of GPs collected the family history, only 24% considered that they know criteria indicating genetics consultation and 39% sufficient knowledge of BRCA1/2 guidelines to answer patients' questions. Twelve% of GPs were aware of the French national guidelines. Among unsatisfied patients, 40% felt that their GP was able to answer (moderately, sufficiently, or completely) specific questions about BRCA1/2 care as compared with 81% in satisfied patients. Only 33% of GPs reported being informed directly by the geneticist about the patients' results. GPs' main expectations for their role in BRCA1/2 carrier care were psychological support and informing relatives about screening (72% and 71%, respectively), which contrasts with the perceptions of patients, who mainly requested medical advice for BRCA1/2‐related care (51%). Conclusion: There is an important need for GP training and enhancing interactions between GPs and geneticists to improve the GP's role in BRCA1/2 screening and management. This work points out the crucial need to improve GPs' medical training in indications for tests and BRCA1/2 management guidelines. It also reports a major expectation of the mutation carriers for a higher involvement of GPs in their medical care. [ABSTRACT FROM AUTHOR]

Abstract: Myotonic dystrophy type 1 (DM1) is a dominant multisystemic disorder associated with high variability of symptoms and anticipation. DM1 is caused by an unstable CTG repeat expansion that usually increases in successive generations and tissues. DM1 family pedigrees have shown that ∼90% and 10% of transmissions result in expansions and contractions of the CTG repeat, respectively. To date, the mechanisms of CTG repeat contraction remain poorly documented in DM1. In this report, we identified two new DM1 families with apparent contractions and no worsening of DM1 symptoms in two and three successive maternal transmissions. A new and unique CAG interruption was found in 5′ of the CTG expansion in one family, whereas multiple 5′ CCG interruptions were detected in the second family. We showed that these interruptions are associated with maternal intergenerational contractions and low somatic mosaicism in blood. By specific triplet‐prime PCR, we observed that CTG repeat changes (contractions/expansions) occur preferentially in 3′ of the interruptions for both families. [ABSTRACT FROM AUTHOR]

Abstract: Autosomal recessive microcephaly or microcephaly primary hereditary (MCPH) is a genetically heterogeneous neurodevelopmental disorder characterized by a reduction in brain volume, indirectly measured by an occipitofrontal circumference (OFC) 2 standard deviations or more below the age‐ and sex‐matched mean (−2SD) at birth and −3SD after 6 months, and leading to intellectual disability of variable severity. The abnormal spindle‐like microcephaly gene (ASPM), the human ortholog of the Drosophila melanogaster “abnormal spindle” gene (asp), encodes ASPM, a protein localized at the centrosome of apical neuroprogenitor cells and involved in spindle pole positioning during neurogenesis. Loss‐of‐function mutations in ASPM cause MCPH5, which affects the majority of all MCPH patients worldwide. Here, we report 47 unpublished patients from 39 families carrying 28 new ASPM mutations, and conduct an exhaustive review of the molecular, clinical, neuroradiological, and neuropsychological features of the 282 families previously reported (with 161 distinct ASPM mutations). Furthermore, we show that ASPM‐related microcephaly is not systematically associated with intellectual deficiency and discuss the association between the structural brain defects (strong reduction in cortical volume and surface area) that modify the cortical map of these patients and their cognitive abilities. [ABSTRACT FROM AUTHOR]

Objective IQSEC2 is an X-linked gene associated with intellectual disability ( ID) and epilepsy. Herein we characterize the epilepsy/epileptic encephalopathy of patients with IQSEC2 pathogenic variants. Methods Forty-eight patients with IQSEC2 variants were identified worldwide through Medline search. Two patients were recruited from our early onset epileptic encephalopathy cohort and one patient from personal communication. The 18 patients who have epilepsy in addition to ID are the subject of this study. Information regarding the 18 patients was ascertained by questionnaire provided to the treating clinicians. Results Six affected individuals had an inherited IQSEC2 variant and 12 had a de novo one (male-to-female ratio, 12:6). The pathogenic variant types were as follows: missense (8), nonsense (5), frameshift (1), intragenic duplications (2), translocation (1), and insertion (1). An epileptic encephalopathy was diagnosed in 9 (50%) of 18 patients. Seizure onset ranged from 8 months to 4 years; seizure types included spasms, atonic, myoclonic, tonic, absence, focal seizures, and generalized tonic-clonic ( GTC) seizures. The electroclinical syndromes could be defined in five patients: late-onset epileptic spasms (three) and Lennox-Gastaut or Lennox-Gastaut-like syndrome (two). Seizures were pharmacoresistant in all affected individuals with epileptic encephalopathy. The epilepsy in the other nine patients had a variable age at onset from infancy to 18 years; seizure types included GTC and absence seizures in the hereditary cases and GTC and focal seizures in de novo cases. Seizures were responsive to medical treatment in most cases. All 18 patients had moderate to profound intellectual disability. Developmental regression, autistic features, hypotonia, strabismus, and white matter changes on brain magnetic resonance imaging ( MRI) were prominent features. Significance The phenotypic spectrum of IQSEC2 disorders includes epilepsy and epileptic encephalopathy. Epileptic encephalopathy is a main clinical feature in sporadic cases. IQSEC2 should be evaluated in both male and female patients with an epileptic encephalopathy. [ABSTRACT FROM AUTHOR]

Anophthalmia and microphthalmia are the most severe malformations of the eye, referring to a congenital absence, and a reduced size of the eyeball respectively. More than 20 genes have been shown to be mutated in patients with syndromic and non-syndromic forms of anophthalmia-microphthalmia. In a recent study combining autozygome and exome analysis, a homozygous loss of function mutation in TENM3 (previously named ODZ3) was reported in two siblings with isolated bilateral colobomatous microphthalmia from a consanguineous Saudi family. Herein, we report a third patient (not related to the previously reported family) with bilateral colobomatous microphthalmia and developmental delay in whom genetic studies identified a homozygous TENM3 splicing mutation c.2968-2A>T (p.Val990Cysfs*13). This report supports the association of TENM3 mutations with colobomatous microphthalmia and expands the phenotypic spectrum associated with mutations in this gene. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Intellectual disability (ID) is a frequent feature but is highly clinically andgenetically heterogeneous. The establishment of the precise diagnosis in patients with ID is challenging due to this heterogeneity but crucial for genetic counseling and appropriate care for the patients. Among the etiologies of patients with ID, apparently balanced de novo rearrangements represent 0.6%. Several mechanisms explain the ID in patients with apparently balanced de novo rearrangement. Among them, disruption of a disease gene at the breakpoint, is frequently evoked. In this context, technologies recently developed are used to characterize precisely such chromosomal rearrangements. Here, we report the case of a boy with ID, facial features and autistic behavior who is carrying a de novo balanced reciprocal translocation t(3;7)(q11.2; q11.22)dn. Using microarray analysis, array painting (AP) technology combined with molecular study, we have identified the interruption of the autism susceptibility candidate 2 gene (AUTS2) and EPH receptor A6 gene (EPHA6). We consider that the disruption of AUTS2 explains the phenotype of the patient; the exact role of EPHA6 in human pathology is not well defined. Based on the observation of recurrent germinal and somatic translocations involving AUTS2 and the molecular environment content, we put forward the hypothesis that the likely chromosomal mechanism responsible for the translocation could bedueeither toreplicative stress or to recombination-based mechanisms. [ABSTRACT FROM AUTHOR]

Dysspondyloenchondromatosis is a rare form of generalized enchondromatosis associated with spinal involvement. This skeletal dysplasia is characterized by multiple enchondromas present in vertebrae as well as in metaphyseal and diaphyseal parts of the long tubular bones, post-natal short stature, and early development of kyphoscoliosis. A novel heterozygous missense mutation in COL2A1 was recently identified in a patient with dysspondyloenchondromatosis. This suggests that dysspondyloenchondromatosis might expand the already broad spectrum of type II collagenopathies. Here, we report on a young girl with features of dysspondyloenchondromatosis, specifically short stature, thoracoscoliosis, and generalized enchondromas lesions. Sanger sequencing failed to detect a mutation in COL2A1. We therefore suggest that dysspondyloenchondromatosis is a genetically heterogeneous condition. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Mosaic variegated aneuploidy (MVA) is a rare autosomal recessive disorder characterized by constitutional aneuploidies. Mutations in BUB1B and CEP57 genes, which are involved in mitotic spindle and microtubule stabilization, respectively, are responsible for a subset of patients with MVA. To date, CEP57 mutations have been reported only in four probands. We report on a girl with this disorder due to c.915-925dup11 mutation in CEP57, which predicts p.Leu309ProfsX9 and review the literature in order to facilitate genotype-phenotype correlation. Rhizomelic shortening of the upper limbs, skull anomalies with conserved head circumference, and absence of tumor development could be features suggesting a need for molecular screening of the CEP57 gene in patients with this disorder. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Catel-Manzke syndrome is characterized by hyperphalangism with bilateral deviation of the index fingers and micrognathia with or without cleft palate. Some atypical patients present with additional malformations. No molecular basis is yet available. Most patients have an unremarkable family history but autosomal recessive inheritance has been recently suggested in a consanguineous family with recurrence in sibs. Catel-Manzke syndrome has overlapping features with Desbuquois dysplasia type 1 due to CANT1 (calcium-activated nucleotidase 1) mutations and also with 'chondrodysplasia with joint dislocations, gPAPP type' due to IMPAD1 (Inositol Monophosphatase Domain containing 1) mutations recently reported in four patients, all characterized by short stature, joint dislocations, brachydactyly and cleft palate. The aim of our study was to screen CANT1 and IMPAD1 in Catel-Manzke patients. Three patients were diagnosed as classical Catel-Manzke syndrome and two as Catel-Manzke like patients, based on the presence of additional features. We identified two homozygous loss-of-function IMPAD1 mutations in the two Catel-Manzke like patients (p.Arg187X and p.Ser108ArgfsX48). The phenotype was characterized by severe growth retardation with short and abnormal extremities, cleft palate with micrognathia and knee hyperlaxity. Radiographs of hands and feet revealed numerous accessory bones with abnormally shaped phalanges and carpal synostosis. Based on this report, we concluded that IMPAD1 should be screened for patients with Catel-Manzke and additional features. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Congenital dyserythropoietic anaemia (CDA) type I is a rare, inherited disorder characterised by ineffective erythropoiesis and macrocytic anaemia. Complex bone disease has only occasionally been associated with this disease. CDA I is caused by mutations in the CDAN1 gene encoding for codanin-1. Our aim was to characterise the CDAN1 mutation in eight unrelated patients with sporadic CDA I, three of whom had complex bone disease. Six novel mutations in the CDAN1 gene were identified. In two patients, one mutation and in another, both mutations were elusive. No patient was homozygous for a null-type mutation. However, one patient with complex bone disease was homozygous for a splice-site mutation ( IVS-12+5G > A). Western blotting revealed that codanin-1 synthesis was 65% less than the control. Five single nucleotide polymorphisms (SNPs) previously unreported in the literature or the SNP database were also identified. Although the absence of codanin-1 is probably lethal, the presence of 35% of the protein was compatible with life but was associated with severe clinical manifestations. However, in most patients studied, no correlation could be established between the expected levels of codanin-1 or the nature of the mutation and the severity of the clinical manifestations. [ABSTRACT FROM AUTHOR]

Background: Tetrasomy 21 is a very rare aneuploidy which could clinically resemble a Down syndrome. It was most often described in its partial form than complete. We report the prenatal, pathological and genetic characteristics of a fetus with mosaic complete tetrasomy 21. This is the second well‐documented description of a complete tetrasomy 21 in the literature. Methods: Prenatal and fetal pathological examinations, cytogenetic and molecular analyses were performed to characterize fetal features with tetrasomy 21. Results: Prenatal ultrasound examination revealed an isolated complete atrioventricular septal defect with normal karyotype on amniotic fluid. After termination of pregnancy, clinical examination of the fetus evoked trisomy 21 or Down syndrome. Chromosomal microarray analysis and FISH on lung tissue showed a mosaicism with four copies of chromosome 21 (tetrasomy 21). Conclusion: Our observation and the review of the literature reported the possibility of very weak mosaicism and disease‐causing confined tissue‐specific mosaicism in fetus or alive patients with chromosome 21 aneuploidy, mainly Down syndrome. In case of clinical diagnosis suggestive of Down syndrome, attention must be paid to the risk of false‐negative test due to chromosomal mosaicism (very weak percentage, different tissue distribution). To overcome this risk, it is necessary to privilege the diagnostic techniques without culture step and to increase the number of cells and tissues analyzed, if possible. This study highlights the limits of microarray as the unique diagnostic approach in case of weak mosaic and French cytogenetics guidelines recommend to check anomalies seen in microarray by another technique on the same tissue. [ABSTRACT FROM AUTHOR]

Kabuki syndrome (KS) is now listed in the Human Inborn Errors of Immunity (IEI) Classification. It is a rare disease caused by KMT2D and KDM6A variants, dominated by intellectual disability and characteristic facial features. Recurrently, pathogenic variants are identified in those genes in patients examined for autoimmune cytopenia (AIC), but interpretation remains challenging. This study aims to describe the genetic diagnosis and the clinical management of patients with paediatric-onset AIC and KS. Among 11 patients with AIC and KS, all had chronic immune thrombocytopenic purpura, and seven had Evans syndrome. All had other associated immunopathological manifestations, mainly symptomatic hypogammaglobinaemia. They had a median of 8 (5-10) KS-associated manifestations. Pathogenic variants were detected in KMT2D gene without clustering, during the immunological work-up of AIC in three cases, and the clinical strategy to validate them is emphasized. Eight patients received second-line treatments, mainly rituximab and mycophenolate mofetil. With a median follow-up of 17 (2-31) years, 8/10 alive patients still needed treatment for AIC. First-line paediatricians should be able to recognize and confirm KS in children with ITP or multiple AIC, to provide early appropriate clinical management and specific long-term follow-up. The epigenetic immune dysregulation in KS opens exciting new perspectives., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

Kabuki syndrome (KS, KS1: OMIM 147920 and KS2: OMIM 300867) is caused by pathogenic variations in KMT2D or KDM6A. KS is characterized by multiple congenital anomalies and neurodevelopmental disorders. Growth restriction is frequently reported. Here we aimed to create specific growth charts for individuals with KS1, identify parameters used for size prognosis and investigate the impact of growth hormone therapy on adult height. Growth parameters and parental size were obtained for 95 KS1 individuals (41 females). Growth charts for height, weight, body mass index (BMI) and occipitofrontal circumference were generated in standard deviation values for the first time in KS1. Statural growth of KS1 individuals was compared to parental target size. According to the charts, height, weight, BMI, and occipitofrontal circumference were lower for KS1 individuals than the normative French population. For males and females, the mean growth of KS1 individuals was -2 and -1.8 SD of their parental target size, respectively. Growth hormone therapy did not increase size beyond the predicted size. This study, from the largest cohort available, proposes growth charts for widespread use in the management of KS1, especially for size prognosis and screening of other diseases responsible for growth impairment beyond a calculated specific target size., (© 2019 Wiley Periodicals, Inc.)

Rubinstein-Taybi syndrome (RSTS) is a developmental disorder characterized by a typical face and distal limbs abnormalities, intellectual disability, and a vast number of other features. Two genes are known to cause RSTS, CREBBP in 60% and EP300 in 8-10% of clinically diagnosed cases. Both paralogs act in chromatin remodeling and encode for transcriptional co-activators interacting with >400 proteins. Up to now 26 individuals with an EP300 mutation have been published. Here, we describe the phenotype and genotype of 42 unpublished RSTS patients carrying EP300 mutations and intragenic deletions and offer an update on another 10 patients. We compare the data to 308 individuals with CREBBP mutations. We demonstrate that EP300 mutations cause a phenotype that typically resembles the classical RSTS phenotype due to CREBBP mutations to a great extent, although most facial signs are less marked with the exception of a low-hanging columella. The limb anomalies are more similar to those in CREBBP mutated individuals except for angulation of thumbs and halluces which is very uncommon in EP300 mutated individuals. The intellectual disability is variable but typically less marked whereas the microcephaly is more common. All types of mutations occur but truncating mutations and small rearrangements are most common (86%). Missense mutations in the HAT domain are associated with a classical RSTS phenotype but otherwise no genotype-phenotype correlation is detected. Pre-eclampsia occurs in 12/52 mothers of EP300 mutated individuals versus in 2/59 mothers of CREBBP mutated individuals, making pregnancy with an EP300 mutated fetus the strongest known predictor for pre-eclampsia. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Syndromic obesity is defined by the association of obesity with one or more feature(s) including developmental delay, dysmorphic traits, and/or congenital malformations. Over 25 syndromic forms of obesity have been identified. However, most cases remain of unknown etiology. The aim of this study was to identify new candidate loci associated with syndromic obesity to find new candidate genes and to better understand molecular mechanisms involved in this pathology. We performed oligonucleotide microarray-based comparative genomic hybridization in a cohort of 100 children presenting with syndromic obesity of unknown etiology, after exhaustive clinical, biological, and molecular studies. Chromosomal copy number variations were detected in 42% of the children in our cohort, with 23% of patients with potentially pathogenic copy number variants. Our results support that chromosomal rearrangements are frequently associated with syndromic obesity with a variety of contributory genes having relevance to either obesity or developmental delay. A list of inherited or apparently de novo duplications and deletions including their enclosed genes and not previously linked to syndromic obesity was established. Proteins encoded by several of these genes are involved in lipid metabolism (ACOXL, MSMO1, MVD, and PDZK1) linked with nervous system function (BDH1 and LINGO2), neutral lipid storage (PLIN2), energy homeostasis and metabolic processes (CDH13, CNTNAP2, CPPED1, NDUFA4, PTGS2, and SOCS6)., (© 2014 Wiley Periodicals, Inc.)

Objective: Familial Mediterranean fever (FMF) is an autosomal-recessive disorder that is common in Armenian, Turkish, Arab, and Sephardic Jewish populations. Its clinical diagnosis is one of exclusion, with the patients displaying nonspecific symptoms related to serosal inflammation. MEFV gene analysis has provided the first objective diagnostic criterion for FMF. However, in the absence of an identified mutation (NI/NI genotype), both the sensitivity of the molecular analyses and the involvement of the MEFV gene in FMF are called into question. The present study was designed to further evaluate the diagnostic value of MEFV analysis in another population of Mediterranean extraction., Methods: The MEFV gene was screened for mutations in 50 patients living in Karabakh (near Armenia) who fulfilled the established criteria for FMF. In addition, we analyzed published series of patients from the above-mentioned at-risk populations., Results: The mutation spectrum in Karabakhian patients, which consisted of only 6 mutations (with 26% of NI alleles), differed from that reported in Armenian patients. Strikingly, among patients from Karabakh and among all classically affected populations, the distribution of genotypes differed dramatically from Hardy-Weinberg equilibrium (P = 0.0016 and P < 0.00001, respectively). These results, combined with other population genetics-based data, revealed the existence of an FMF-like condition that, depending on the patients' ancestry, was shown to affect 85-99% of those with the NI/NI genotype., Conclusion: These data illuminate the meaning of negative results of MEFV analyses and show that in all populations evaluated, most patients with the NI/NI genotype had disease that mimicked FMF and was unrelated to the MEFV gene. Our findings also demonstrate the high sensitivity of a search for very few mutations in order to perform a molecular diagnosis of MEFV-related FMF.