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SALL1 heterozygous pathogenic variants cause Townes–Brocks syndrome (TBS), a condition with variable clinical presentation. The main features are a stenotic or imperforate anus, dysplastic ears, and thumb malformations, and other common concerns are hearing impairments, foot malformations, and renal and heart defects. Most of the pathogenic SALL1 variants are nonsense and frameshift, likely escaping nonsense-mediated mRNA decay and causing disease via a dominant-negative mechanism. Haploinsufficiency may result in mild phenotypes, but only four families with distinct SALL1 deletions have been reported to date, with a few more being of larger size and also affecting neighboring genes. We report on a family with autosomal dominant hearing impairment and mild anal and skeletal anomalies, in whom a novel 350 kb SALL1 deletion, spanning exon 1 and the upstream region, was identified by array comparative genomic hybridization. We review the clinical findings of known individuals with SALL1 deletions and point out that the overall phenotype is milder, especially when compared with individuals who carry the recurrent p.Arg276Ter mutation, but with a possible higher risk of developmental delay. Chromosomal microarray analysis is still a valuable tool in the identification of atypical/mild TBS cases, which are likely underestimated.

Background Adult polycystic kidney disease (ADPKD) still represents a major cause of renal failure and intracranial aneurisms (IA) have a higher prevalence in ADPKD than in the general population. Current guidelines suggest performing brain MRI only in the subjects with a positive familiar history of IAs or subarachnoid hemorrhage (SAH). This is a retrospective case-control analysis to evaluate the usefulness of a MR screening program in ADPKD patients. Methods We retrospectively analyzed all ADPKD patients followed in our outpatient clinic between 2016 and 2019 who underwent a brain MRI screening. We evaluated the presence of IAs and others brain abnormalities and compared our results with a non-ADPKD population (n = 300). We performed univariate and multivariate regression analysis to evaluate if general and demographic features, laboratory findings, clinical parameters and genetic test results correlated with IAs or other brain abnormalities presence. Results Among the patients evaluated 17 out of 156 (13.6%) ADPKD patients had IAs, compared to 16 out of 300 (5.3%) non-ADPKD controls (p p p Conclusion In our population ADPKD patients showed a higher prevalence of IAs, AC and arterial variants compared to non-ADPKD. Most of the IAs were found in patients presenting a PKD1 mutation. We found a significant number of alterations even in those patients without a family history of IAs or SAH. The practice of submitting only patients with familial IAs or kidney transplantation candidates to MRI scan should be re-evaluated.

BackgroundKoolen-de Vries syndrome (KdVS) is a multisystem neurodevelopmental disorder caused by 17q21.31 deletions or mutations in KANSL1. It was mainly described in children.MethodsA retrospective study on 9 subjects aged 19–45 years and revision of 18 literature patients, with the purpose to get insights into the phenotypic evolution with time, and into the clinical manifestations in adulthood.ResultsSeven patients had a 17q21.31 deletion and two a point mutation in KANSL1. All had intellectual disability, which was mild in five (56%) and moderate in four (44%). Epilepsy was diagnosed in four subjects (44%), with onset from 1 to 7 years and full remission before 9 years in 3/4 patients. Scoliosis affected seven individuals (77.7%) and it was substantially stable with age in 5/7 patients, allowing for simple daily activities. Two subjects had severely progressive scoliosis, which was surgically corrected. Overweight or true obesity did occur after puberty in six patients (67%). Behaviour abnormalities were recorded in six patients (67%). The facial phenotype slightly evolved with time to include thick eyebrows, elongated nose and pronounced pointed chin. Despite behaviour abnormalities, happy disposition and sociable attitudes were common. Half of patients had fluent language and were good at writing and reading. Rich language, although limited to single words or short sentences, and very limited or absent skills in writing and reading were observed in the remaining patients. Autonomy in daily activities and personal care was usually limited.ConclusionsDistinctive features in adult KdVS subjects include intellectual disability, overweight/obesity, behaviour abnormalities with preserved social interest, ability in language, slight worsening of the facial phenotype and no seizures.

ZMYND8 encodes a multidomain protein that serves as a central interactive hub for coordinating critical roles in transcription regulation, chromatin remodeling, regulation of super-enhancers, DNA damage response and tumor suppression. We delineate a novel neurocognitive disorder caused by variants in the ZMYND8 gene.An international collaboration, exome sequencing, molecular modeling, yeast two-hybrid assays, analysis of available transcriptomic data and a knockdown Drosophila model were used to characterize the ZMYND8 variants.ZMYND8 variants were identified in 11 unrelated individuals; 10 occurred de novo and one suspected de novo; 2 were truncating, 9 were missense, of which one was recurrent. The disorder is characterized by intellectual disability with variable cardiovascular, ophthalmologic and minor skeletal anomalies. Missense variants in the PWWP domain of ZMYND8 abolish the interaction with Drebrin and missense variants in the MYND domain disrupt the interaction with GATAD2A. ZMYND8 is broadly expressed across cell types in all brain regions and shows highest expression in the early stages of brain development. Neuronal knockdown of the DrosophilaZMYND8 ortholog results in decreased habituation learning, consistent with a role in cognitive function.We present genomic and functional evidence for disruption of ZMYND8 as a novel etiology of syndromic intellectual disability.

BackgroundA neurodevelopmental syndrome was recently reported in four patients withSOX4heterozygous missense variants in the high-mobility-group (HMG) DNA-binding domain. The present study aimed to consolidate clinical and genetic knowledge of this syndrome.MethodsWe newly identified 17 patients withSOX4variants, predicted variant pathogenicity using in silico tests and in vitro functional assays and analysed the patients’ phenotypes.ResultsAll variants were novel, distinct and heterozygous. Seven HMG-domain missense and five stop-gain variants were classified as pathogenic or likely pathogenic variant (L/PV) as they precluded SOX4 transcriptional activity in vitro. Five HMG-domain and non-HMG-domain missense variants were classified as of uncertain significance (VUS) due to negative results from functional tests. When known, inheritance was de novo or from a mosaic unaffected or non-mosaic affected parent for patients with L/PV, and from a non-mosaic asymptomatic or affected parent for patients with VUS. All patients had neurodevelopmental, neurological and dysmorphic features, and at least one cardiovascular, ophthalmological, musculoskeletal or other somatic anomaly. Patients with L/PV were overall more affected than patients with VUS. They resembled patients with other neurodevelopmental diseases, including theSOX11-related and Coffin-Siris (CSS) syndromes, but lacked the most specific features of CSS.ConclusionThese findings consolidate evidence of a fairly non-specific neurodevelopmental syndrome due toSOX4haploinsufficiency in neurogenesis and multiple other developmental processes.

Hearing loss (HL) is the most common sensory impairment, and it is characterized by a high clinical/genetic heterogeneity. Here we report the identification of dual molecular diagnoses (i.e., mutations at two loci that lead to the expression of two Mendelian conditions) in a series of families affected by non-syndromic and syndromic HL. Eighty-two patients who displayed HL as a major clinical feature have been recruited during the last year. After an accurate clinical evaluation, individuals have been analyzed through whole-exome sequencing (WES). This protocol led to the identification of seven families characterized by the presence of a dual diagnosis. In particular, based on the clinical and genetic findings, patients have been classified into two groups: (a) patients with HL and distinct phenotypes not fitting in a known syndrome due to mutations at two loci (e.g., HL in association with Marfan syndrome) and (b) patients with two genes involved in HL phenotype (e.g., TMPRSS3 and MYH14). These data highlight for the first time the high prevalence of dual molecular diagnoses in HL patients and suggest that they should be considered especially for those cases that depart from the expected clinical manifestation or those characterized by a significant intra-familiar variability.

Structural variants (SVs) can affect protein-coding sequences as well as gene regulatory elements. However, SVs disrupting protein-coding sequences that also function as cis-regulatory elements remain largely uncharacterized. Here, we show that craniosynostosis patients with SVs containing the histone deacetylase 9 (HDAC9) protein-coding sequence are associated with disruption of TWIST1 regulatory elements that reside within the HDAC9 sequence. Based on SVs within the HDAC9‐TWIST1 locus, we defined the 3′-HDAC9 sequence as a critical TWIST1 regulatory region, encompassing craniofacial TWIST1 enhancers and CTCF sites. Deletions of either Twist1 enhancers (eTw5-7Δ/Δ) or CTCF site (CTCF-5Δ/Δ) within the Hdac9 protein-coding sequence led to decreased Twist1 expression and altered anterior/posterior limb expression patterns of SHH pathway genes. This decreased Twist1 expression results in a smaller sized and asymmetric skull and polydactyly that resembles Twist1+/− mouse phenotype. Chromatin conformation analysis revealed that the Twist1 promoter interacts with Hdac9 sequences that encompass Twist1 enhancers and a CTCF site, and that interactions depended on the presence of both regulatory regions. Finally, a large inversion of the entire Hdac9 sequence (Hdac9INV/+) in mice that does not disrupt Hdac9 expression but repositions Twist1 regulatory elements showed decreased Twist1 expression and led to a craniosynostosis-like phenotype and polydactyly. Thus, our study elucidates essential components of TWIST1 transcriptional machinery that reside within the HDAC9 sequence. It suggests that SVs encompassing protein-coding sequences could lead to a phenotype that is not attributed to its protein function but rather to a disruption of the transcriptional regulation of a nearby gene.

The aim of our study was to evaluate the association between intracranial arterial tortuosity and cardiovascular outcome in patients with Loeys-Dietz syndrome (LDS). We performed a retrospective analysis of all patients with genetically confirmed LDS who underwent at least one brain MRA at our institution (n = 32); demographic and clinical features were evaluated in relation to the tortuosity of intracranial arteries as measured by tortuosity index (TI), which was calculated using the formula: [(centerline length) / (straight-line length)-1] × 100. Receiver operating characteristic curve analysis for intracranial TI and the binary end point of aortic surgery showed vertebrobasilar TI (VBTI) to be the best classifier among the examined arterial segments (AUC = 0.822). Patients with higher VBTI showed a greater incidence of aortic surgery (p 0.001) and underwent more surgical and endovascular procedures (p = 0.006), with a higher rate of operations (p = 0.002). Kaplan-Meier analysis showed a significantly longer surgery-free survival in patients with lower arterial tortuosity (p 0.001). At multivariate analysis, higher VBTI was associated with an increased risk of surgery (p 0.001), which was independent of gene mutation and patient age. Increased VBTI is a marker of adverse cardiovascular outcome in patients with LDS, which can be easily measured on brain MRA, and may be useful in the management of this heterogeneous patient population.

Ring chromosome 10 [r(10)] syndrome is a rare genetic condition, currently described in the medical literature in a small number of case report studies. Typical clinical features include microcephaly, short stature, facial dysmorphisms, ophthalmologic abnormalities and genitourinary malformations. We report a novel case of r(10) syndrome and review the neurological and neuroradiological phenotypes of the previously described cases. Our patient, a 3 year old Italian girl, represents the 20th case of r(10) syndrome described to date. Intellectual disability/developmental delay (ID/DD), microcephaly, strabismus, hypotonia, stereotyped/aggressive behaviors and electroencephalographic abnormalities were identified in our patient, and in a series of previous cases. A brain MRI disclosed a complex malformation involving both the vermis and cerebellar hemispheres, in the literature, posterior cranial fossa abnormalities were documented by CT scan in another case. Two genes deleted in our case (ZMYND11 in 10p and EBF3 in 10q) are involved in autosomal dominant neurodevelopmental disorders, characterized by different expressions of brain and posterior cranial fossa abnormalities, ID/DD, hypotonia and behavioral problems. Our case expands the neurological and neuroradiological phenotype of r(10) syndrome. Although r(10) syndrome represents an extremely rare condition, with a clinical characterization limited to case reports, the recurrence of specific neurological and neuroradiological features suggests the need for specific genotype-phenotype studies.

Structural variants (SVs) can affect protein-coding sequences as well as gene regulatory elements. However, SVs disrupting protein-coding sequences that also function as cis-regulatory elements remain largely uncharacterized. Here, we show that craniosynostosis patients with SVs containing the Histone deacetylase 9 (HDAC9) protein-coding sequence are associated with disruption ofTWIST1regulatory elements that reside withinHDAC9sequence. Based on SVs within theHDAC9-TWIST1locus, we defined the 3’ HDAC9 sequence (~500Kb) as a criticalTWIST1regulatory region, encompassing craniofacialTWIST1enhancers and CTCF sites. Deletions of eitherTwist1enhancers (eTw5-7Δ/Δ) or Ctcf site (CtcfΔ/Δ) within the Hdac9 protein-coding sequence in mice led to decreasedTwist1expression and altered anterior\posterior limb expression patterns of Shh pathway genes. This decreased Twist1 expression results in a smaller sized and asymmetric skull and polydactyly that resemblesTwist1+/-mouse phenotype. Chromatin conformation analysis revealed thatthe Twist1promoter region interacts withHdac9sequences that encompassTwist1enhancers and a Ctcf site and that interactions depended on the presence of both regulatory regions. Finally, a large inversion of the entireHdac9sequence (Hdac9INV/+) in mice that does not disruptHdac9expression but repositionsTwist1regulatory elements showed decreasedTwist1expression and led to a craniosynostosis-like phenotype and polydactyly. Thus, our study elucidated essential components ofTWIST1transcriptional machinery that reside within theHDAC9sequence, suggesting that SVs, encompassing protein-coding sequence, such asHDAC9, could lead to a phenotype that is not attributed to its protein function but rather to a disruption of the transcriptional regulation of a nearby gene, such asTWIST1.

Junctional epidermolysis bullosa (JEB) is a clinically and genetically heterogeneous skin fragility disorder frequently caused by mutations in genes encoding the epithelial laminin isoform, laminin-332. JEB patients also present mucosal involvement, including painful corneal lesions. Recurrent corneal abrasions may lead to corneal opacities and visual impairment. Current treatments are merely supportive. We report a novel JEB phenotype distinguished by the complete resolution of skin fragility in infancy and persistent ocular involvement with unremitting and painful corneal abrasions. Biallelic LAMB3 mutations c.3052-5C&gt, G and c.3492_3493delCG were identified as the molecular basis for this phenotype, with one mutation being a hypomorphic splice variant that allows residual wild-type laminin-332 production. The reduced laminin-332 level was associated with impaired keratinocyte adhesion. Then, we also investigated the therapeutic power of a human amniotic membrane (AM) eyedrop preparation for corneal lesions. AM were isolated from placenta donors, according to a procedure preserving the AM biological characteristics as a tissue, and confirmed to contain laminin-332. We found that AM eyedrop preparation could restore keratinocyte adhesion in an in vitro assay. Of note, AM eyedrop administration to the patient resulted in long-lasting remission of her ocular manifestations. Our findings suggest that AM eyedrops could represent an effective, non-invasive, simple-to-handle treatment for corneal lesions in patients with JEB and possibly other EB forms.

Neurofibromatosis type I, a genetic condition due to pathogenic variants in the NF1 gene, is burdened by a high rate of complications, including neoplasms, which increase morbidity and mortality for the disease. We retrospectively re-evaluated the NF1 gene variants found in the period 2000-2019 and we studied for genotype/phenotype correlations of disease complications and neoplasms 34 variants, which were shared by at least two unrelated families (range 2-11) for a total 141 of probands and 21 relatives affected by Neurofibromatosis type I. Recurrent variants could be ascribed to the most common mutational mechanisms (C to T transition, microsatellite slippage, non-homologous recombination). In genotype/phenotype correlations, the variants p.Arg440*, p.Tyr489Cys, and p.Arg1947*, together with the gross gene deletions, displayed the highest rates of complications. When considering neoplasms, carriers of variants falling in the extradomain region at the 5' end of NF1 had a lower age-related cancer frequency than the rest of the gene sequence, showing a borderline significance (p = 0.045), which was not conserved after correction with covariates. We conclude that (1) hotspots in NF1 occur via different mutational mechanisms, (2) several variants are associated with high rates of complications and cancers, and (3) there is an initial evidence toward a lower cancer risk for carriers of variants in the 5' end of the NF1 gene although not significant at the multivariate analysis.

Background and ObjectivesPurine-rich element-binding protein A (PURA) gene encodes Pur-α, a conserved protein essential for normal postnatal brain development. Recently, a PURA syndrome characterized by intellectual disability, hypotonia, epilepsy, and dysmorphic features was suggested. The aim of this study was to define and expand the phenotypic spectrum of PURA syndrome by collecting data, including EEG, from a large cohort of affected patients.MethodsData on unpublished and published cases were collected through the PURA Syndrome Foundation and the literature. Data on clinical, genetic, neuroimaging, and neurophysiologic features were obtained.ResultsA cohort of 142 patients was included. Characteristics of the PURA syndrome included neonatal hypotonia, feeding difficulties, and respiratory distress. Sixty percent of the patients developed epilepsy with myoclonic, generalized tonic-clonic, focal seizures, and/or epileptic spasms. EEG showed generalized, multifocal, or focal epileptic abnormalities. Lennox-Gastaut was the most common epilepsy syndrome. Drug refractoriness was common: 33.3% achieved seizure freedom. We found 97 pathogenic variants in PURA without any clear genotype-phenotype associations.DiscussionThe PURA syndrome presents with a developmental and epileptic encephalopathy with characteristics recognizable from neonatal age, which should prompt genetic screening. Sixty percent have drug-resistant epilepsy with focal or generalized seizures. We collected more than 90 pathogenic variants without observing overt genotype-phenotype associations.

Background Alport syndrome (ATS) is a hereditary progressive hematuric nephropathy associated with sensorineural deafness and ocular abnormalities, which is caused by mutations in the COL4A5 gene (X‐linked ATS) and in two autosomal genes, COL4A4 and COL4A3, responsible of both recessive ATS and, when present in heterozygosity, of a spectrum of phenotypes ranging from isolated hematuria to frank renal disease. Methods Retrospective analysis of the clinical and genetic features of 76 patients from 34 unrelated ATS families (11 with mutations in COL4A5, 11 in COL4A3, and 12 in COL4A4) and genotype/phenotype correlation for the COL4A3/COL4A4 heterozygotes (34 patients from 14 families). Results Eight (24%) of the 34 heterozygous COL4A3 and COL4A4 carriers developed renal failure at a mean age of 57 years, with a significantly lower risk than hemizygous COL4A5 or double heterozygous COL4A3/COL4A4 carriers (p, Heterozygotes for COL4A3 and COL4A4 variants showed a significantly lower risk than hemizygous COL4A5 or double heterozygous COL4A3/COL4A4 carriers (p

BACKGROUND AND PURPOSE: The association of arterial tortuosity and connective tissue diseases is widely reported in the literature, but only a few studies were based on a quantitative evaluation of this arterial phenotype, and none of the latter examined the intracranial vasculature. The aim of this study was to evaluate the degree of intracranial arterial tortuosity in patients with Marfan syndrome and those with Loeys-Dietz syndrome, and to assess its usefulness in the differential diagnosis. MATERIALS AND METHODS: We performed a retrospective analysis of 68 patients with genetically confirmed Marfan syndrome (n = 36) or Loeys-Dietz syndrome (n = 32), who underwent at least 1 MRA of the brain at our institution. Fifty-two controls were randomly selected among patients who presented with headache and without any known comorbidity. Tortuosity indexes of 4 intracranial arterial segments were measured on a 3D volume-rendered angiogram by using the following formula: ( centerline length straight ‐ line length − 1 ) × 100 . RESULTS: Both Marfan syndrome and Loeys-Dietz syndrome showed a significantly higher tortuosity index compared with controls in all examined vessels. The tortuosity index of the vertebrobasilar system showed an excellent interrater reliability (intraclass correlation coefficient, 0.99) and was the strongest independent predictor of Loeys-Dietz syndrome in patients with connective tissue disease (P = .002), with a 97% specificity for this pathology when its value was > 60. CONCLUSIONS: The tortuosity index of intracranial arteries is an easily calculated and highly reproducible measure, which shows a high specificity for Marfan syndrome and Loeys-Dietz syndrome and may be useful in differentiating these 2 entities.

Hearing loss (HL), both syndromic (SHL) and non-syndromic (NSHL), is the most common sensory disorder, affecting ~460 million people worldwide. More than 50% of the congenital/childhood cases are attributable to genetic causes, highlighting the importance of genetic testing in this class of disorders. Here we applied a multi-step strategy for the molecular diagnosis of HL in 125 patients, which included: (1) an accurate clinical evaluation, (2) the analysis of GJB2, GJB6, and MT-RNR1 genes, (3) the evaluation STRC-CATSPER2 and OTOA deletions via Multiplex Ligation Probe Amplification (MLPA), (4) Whole Exome Sequencing (WES) in patients negative to steps 2 and 3. Our approach led to the characterization of 50% of the NSHL cases, confirming both the relevant role of the GJB2 (20% of cases) and STRC deletions (6% of cases), and the high genetic heterogeneity of NSHL. Moreover, due to the genetic findings, 4% of apparent NSHL patients have been re-diagnosed as SHL. Finally, WES characterized 86% of SHL patients, supporting the role of already know disease-genes. Overall, our approach proved to be efficient in identifying the molecular cause of HL, providing essential information for the patients&rsquo, future management.

Koolen-de Vries syndrome (KdVS) is a multisystem neurodevelopmental disorder caused by 17q21.31 deletions or mutations inA retrospective study on 9 subjects aged 19-45 years and revision of 18 literature patients, with the purpose to get insights into the phenotypic evolution with time, and into the clinical manifestations in adulthood.Seven patients had a 17q21.31 deletion and two a point mutation inDistinctive features in adult KdVS subjects include intellectual disability, overweight/obesity, behaviour abnormalities with preserved social interest, ability in language, slight worsening of the facial phenotype and no seizures.

Background and Aims Autosomal dominant polycystic kidney disease (ADPKD) is a multisystemic disease characterized by the progressive development of bilateral renal cysts, resulting in enlargement of the kidney volume due to cystic formations, hypertension, haematuria, and loss of renal function. Recent advances in genomics have contributed to have a better understanding of the pathogenesis of the disease suggesting new treatment strategies to inhibit or delay cysts formation and expansion.Since 2015, the European Medicines Agency approved Vaptans as therapy to slow the growth of kidney volume and the decline in kidney function in patients defined rapid progressors. In 2016 European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Working Groups on Inherited Kidney Disorders and European Renal Best Practice (WGIKD/ ERBP) published a position statement for definition of rapid progression. These recommendations included two algorithms to assess indications for initiation of ADPKD treatment. They selected three criteria based on: 1) the relationship between TKV(total kidney volume) and the decline in renal function according CRISP study, using Mayo Clinic Score 2) eGFR slope with an average ≥2.5 mL/min/1.73 m2/ yearly loss of renal function over a period of 5 yearsor 3) the link between genetic mutation and clinical information study using Propkd score.A 5 –years follow-up is not always available to achieve the criteria for rapid progressor, therefore the use of scores in clinical practice is widespread.In this scenario both scores (MAYO and PRO-PKD) are able to define rapid progressor patients and it is possible to use them alternatively as reported in literature. The aim of this study is to evaluate the prognostic scores in a real life experience. Method All ADPKD patients in follow-up in our Nephrology Unit from January 2017 to July 2019 were included in the study. Descriptive statistics were used to summarize demographic and clinical characteristics. Therefore we classified them for TKV, genetic mutation, renal function, Mayo score and Propkd score. Rapid progression was defined as 1C-D-E Mayo and high risk PRO PKD while non rapid progressors was 1A-1B mayo and low and intermediate PRO-PKD. Kappa statistic was used to determinate the concordance between Mayo and PROPKD score. Change in renal function within patients with the same class of score where analysed using Paired Wilcoxon signed rank sum test. Results We examined75 patients, 78% between 18-50 years, equally distributed for sex. The results shown thatdisease was more frequent familiar (88 %) witha percentage of mutations of PKD1 versus PKD2 mutation (90,7%/9,3%). 31patients (41%) had a GFR between 45-89 ml/min, 52patients (69%) achieved the criteria for nephromegaly according guideline (TKV > 750CC). Respectively 76% (57pt) and 21%(16pt) were defined as rapid progressors for Mayo score ad Propkd score. The slope of GFR was worse in patients defined rapid progressor in spite of non rapidprogressor according MAYO score (-2,8 ml/min vs 0,3 ml/min) as for propkd classification (-3 vs - 1,75ml/min). Only for 15 patients the results were concordant for this two scores,43 patients identified as rapid progressor for Mayo score were non rapid progressor for Propkd score, in the same way 2 patients classified for Propkd were not rapid progressor for Mayo score. K of Coen of 0,07. Conclusion High risk patients present a significant decline in renal function in the first year with both score systems, confirming results of previous studies. Currently the scores used to define rapid progressors select patients differently. Concordance between scores il low (K of Cohen 0,076). The Propkd score is more selective compared to Mayo score. NeverthelessProPKD allows to identify some rapid progressor patients excluded from the use of the Mayo score only. The combined use of scoring may however increases the ability to identify progressive patients.

KBG syndrome is an autosomal dominant disorder caused by pathogenic variants within ANKRD11 or deletions of 16q24.3 which include ANKRD11. It is characterized by distinctive facial features, developmental delay, short stature, and skeletal anomalies. We report 12 unrelated patients where a clinical diagnosis of KBG was suspected and confirmed by targeted analyses. Nine patients showed a point mutation in ANKRD11 (none of which were previously reported) and 3 carried a 16q24.3 deletion. All patients presented with typical facial features and macrodontia. Skeletal abnormalities were constant, and the majority of patients showed joint stiffness. Three patients required growth hormone treatment with a significant increase of height velocity. Brain malformations were identified in 8 patients. All patients showed behavioral abnormalities and most had developmental delay. Two patients had hematological abnormalities. We emphasize that genetic analysis of ANKRD11 can easily reach a detection rate higher than 50% thanks to clinical phenotyping, although it is known that a subset of ANKRD11-mutated patients show very mild features and will be more easily identified through the implementation of gene panels or exome sequencing. Joint stiffness was reported previously in few patients, but it seems to be a common feature and can be helpful for the diagnosis. Hematological abnormalities could be present and warrant a specific follow-up.

There have been few clinical or scientific reports of autosomal dominant tubulointerstitial kidney disease due to REN mutations (ADTKD-REN), limiting characterization. To further study this, we formed an international cohort characterizing 111 individuals from 30 families with both clinical and laboratory findings. Sixty-nine individuals had a REN mutation in the signal peptide region (signal group), 27 in the prosegment (prosegment group), and 15 in the mature renin peptide (mature group). Signal group patients were most severely affected, presenting at a mean age of 19.7 years, with the prosegment group presenting at 22.4 years, and the mature group at 37 years. Anemia was present in childhood in 91% in the signal group, 69% prosegment, and none of the mature group. REN signal peptide mutations reduced hydrophobicity of the signal peptide, which is necessary for recognition and translocation across the endoplasmic reticulum, leading to aberrant delivery of preprorenin into the cytoplasm. REN mutations in the prosegment led to deposition of prorenin and renin in the endoplasmic reticulum-Golgi intermediate compartment and decreased prorenin secretion. Mutations in mature renin led to deposition of the mutant prorenin in the endoplasmic reticulum, similar to patients with ADTKD-UMOD, with a rate of progression to end stage kidney disease (63.6 years) that was significantly slower vs. the signal (53.1 years) and prosegment groups (50.8 years) (significant hazard ratio 0.367). Thus, clinical and laboratory studies revealed subtypes of ADTKD-REN that are pathophysiologically, diagnostically, and clinically distinct.

Poikiloderma with neutropenia (PN) is a genodermatosis currently described in 77 patients, all presenting with early-onset poikiloderma, neutropenia, and several additional signs. Biallelic loss-of-function mutations in USB1 gene are detected in all molecularly tested patients but genotype-phenotype correlation remains elusive. Cancer predisposition is recognized among PN features and pathogenic variants found in patients who developed early in life myelodysplasia (n = 12), acute myeloid leukemia (n = 2), and squamous cell carcinoma (n = 2) should be kept into account in management and follow-up of novel patients. This will hopefully allow achieving data clustered on specific mutations relevant to oncological surveillance of the carrier patients. We describe the clinical features of three unreported PN patients and characterize their USB1 pathogenic variants by transcript analysis to get insights into the effect on the overall phenotype and disease evolution. A Turkish boy is homozygous for the c.531delA deletion, a recurrent mutation in Turkey; an adult Italian male is compound heterozygous for two nonsense mutations, c.243G>A and c.541C>T, while an Italian boy is homozygous for the splicing c.683_693+1del variant. The identified mutations have already been reported in PN patients who developed hematologic or skin cancer. Aberrant mRNAs of all four mutated alleles could be identified confirming that transcripts of USB1 main isoform either carrying stop codons or mis-spliced may at least partially escape nonsense-mediated decay. Our study addresses the need of gathering insights on genotype-phenotype correlations in newly described PN patients, by transcript analysis and information on disease evolution of reported patients with the same pathogenic variants.

We report a patient with developmental delay, brachydactyly type E, short stature, and tetralogy of Fallot. Brachydactyly-mental retardation syndrome (BDMR) was suspected based on the phenotype; however, array CGH excluded a 2q37 deletion, but identified a deletion encompassing the SHOX gene. BDMR is characterized by cognitive impairment, skeletal abnormalities involving hands and feet, short stature, and overweight. Most affected individuals carry relatively large 2q37 deletions encompassing HDAC4. This gene encodes a histone deacetylase involved in epigenetic regulation of cell growth and differentiation, specifically during endochondral bone formation in chondrocyte hypertrophy. Since SHOX haploinsufficiency can cause skeletal defects and short stature but would not fully explain the clinical picture of this patient, exome sequencing was performed, and a heterozygous HDAC8 frameshift mutation was identified. HDAC8 is a distinct histone deacetylase involved in cohesin recycling and is responsible for an X-linked dominant Cornelia de Lange-like phenotype. A new blended clinical phenotype may be explained by the result of a dual molecular diagnosis, which represents a combination of 2 independent genetic defects, with relevant implications for genetic counseling, clinical management, and prognosis.

In clinical genetics, the need to discriminate between benign and pathogenic variants identified in patients with neurodevelopmental disorders is an absolute necessity. Copy number variants (CNVs) of small size can enable the identification of genes that are critical for neurologic development. However, assigning a definite association with a specific disorder is a difficult task. Among 328 trios analyzed over seven years of activity in a single laboratory, we identified 19 unrelated patients (5.8%) who carried a small (< 500 kb) de novo CNV. Four patients had an additional independent de novo CNV. Nine had a variant that could be assigned as definitely pathogenic, whereas the remaining CNVs were considered as variants of unknown significance (VUS). We report clinical and molecular findings of patients harboring VUS. We reviewed the medical literature available for genes impacted by CNVs, obtained the probability of truncating loss-of-function intolerance, and compared overlapping CNVs reported in databases. The classification of small non-recurrent CNVs remains difficult but, among our findings, we provide support for a role of SND1 in the susceptibility of autism, describe a new case of the rare 17p13.1 microduplication syndrome, and report an X-linked duplication involving KIF4A and DLG3 as a likely cause of epilepsy.

This study aimed to investigate the potential association between imaging features and cardiovascular outcomes in patients with Loeys-Dietz syndrome (LDS). We performed a retrospective cohort study of 36 patients with LDS and described cardiovascular events and imaging data. We observed different clinical courses in patients with LDS, irrespective of the causative gene. Angular or elongated aortic arch geometry correlated with aortic dissection (R = .39, p = .02), occurrence of the first cardiovascular event before 45 years of age (R = .36, p = .03), and the number of operations (R = 0.47, p = .004), but not with age (R = -.05, p = .79) or the causative gene (R = -0.04, p = .79). The incidences of first cardiovascular events at ages 20, 40, and 60 years were 100, 75, and 56%, respectively, in patients with normal aortic arches, and 74, 39, and 21%, respectively, in patients with angular or elongated aortic arches (log-rank p = .03). Angular or elongated aortic arch geometry is associated with early-onset of disease and a worse cardiovascular outcome in LDS patients. Large multicenter studies are warranted to elucidate the impact of aortic arch morphology evaluation in clinical practice.

BackgroundPontocerebellar hypoplasias (PCH) comprise a group of genetically heterogeneous disorders characterised by concurrent hypoplasia of the pons and the cerebellum and variable clinical and imaging features. The current classification includes 13 subtypes, with ~20 known causative genes. Attempts have been made to delineate the phenotypic spectrum associated to specific PCH genes, yet clinical and neuroradiological features are not consistent across studies, making it difficult to define gene-specific outcomes.MethodsWe performed deep clinical and imaging phenotyping in 56 probands with a neuroradiological diagnosis of PCH, who underwent NGS-based panel sequencing of PCH genes and MLPA for CASK rearrangements. Next, we conducted a phenotype-based unsupervised hierarchical cluster analysis to investigate associations between genes and specific phenotypic clusters.ResultsA genetic diagnosis was obtained in 43 probands (77%). The most common causative gene was CASK, which accounted for nearly half cases (45%) and was mutated in females and occasionally in males. The European founder mutation p.Ala307Ser in TSEN54 and pathogenic variants in EXOSC3 accounted for 18% and 9% of cases, respectively. VLDLR, TOE1 and RARS2 were mutated in single patients. We were able to confirm only few previously reported associations, including jitteriness and clonus with TSEN54 and lower motor neuron signs with EXOSC3. When considering multiple features simultaneously, a clear association with a phenotypic cluster only emerged for EXOSC3.ConclusionCASK represents the major PCH causative gene in Italy. Phenotypic variability associated with the most common genetic causes of PCH is wider than previously thought, with marked overlap between CASK and TSEN54-associated disorders.

Autozygosity-driven exome analysis has been shown effective for identification of genes underlying recessive diseases especially in countries of the so-called Greater Middle East (GME), where high consanguinity unravels the phenotypic effects of recessive alleles and large family sizes facilitate homozygosity mapping. In Italy, as in most European countries, consanguinity is estimated low. Nonetheless, consanguineous Italian families are not uncommon in publications of genetic findings and are often key to new associations of genes with rare diseases. We collected 52 patients from 47 consanguineous families with suspected recessive diseases, 29 originated in GME countries and 18 of Italian descent. We performed autozygosity-driven exome analysis by detecting long runs of homozygosity (ROHs > 1.5Mb) and by prioritizing candidate clinical variants within. We identified a pathogenic synonymous variant that had been previously missed in NARS2 and we increased an initial high diagnostic rate (47%) to 55% by matchmaking our candidate genes and including in the analysis shorter ROHs that may also happen to be autozygous. GME and Italian families contributed to diagnostic yield comparably. We found no significant difference either in the extension of the autozygous genome, or in the distribution of candidate clinical variants between GME and Italian families, while we showed that the average autozygous genome was larger and the mean number of candidate clinical variants was significantly higher (p = 0.003) in mutation-positive than in mutation-negative individuals, suggesting that these features influence the likelihood that the disease is autozygosity-related. We highlight the utility of autozygosity-driven genomic analysis also in countries and/or communities, where consanguinity is not widespread cultural tradition.

Fabry disease is classified as a rare X-linked disease caused by a complete or partial defect of enzyme alpha-galactosidase, due to GLA gene mutations. This disorder leads to intracellular globotriaosylceramide (Gb3) deposition associated with increased Gb3 plasma levels. Most of the symptoms of the disease, involving kidneys, heart and nervous system, result from this progressive Gb3 deposition. The incidence is estimated in 1/50,000 to 1/117,000 in males. Fabry nephropathy begins with microalbuminuria and/or proteinuria, which, in the classic form, appear from childhood. Thus, a progressive decline of renal function can start at a young age, and evolve to kidney failure, requiring dialysis or renal transplantation. Enzyme replacement therapy (ERT), available since 2001 for Fabry disease, has been increasingly introduced into the clinical practice, with overall positive short-term and long-term effects in terms of ventricular hypertrophy and renal function. Kidney transplantation represents a relevant therapeutic option for Fabry nephropathy management, for patients reaching end-stage renal disease, but little is known about long-term outcomes, overall patient survival or the possible role of ERT after transplant. The purpose of this review is to analyze the literature on every aspect related to kidney transplantation in patients with Fabry nephropathy: from the analysis of transplant outcomes, to the likelihood of disease recurrence, up to the effects of ERT and its possible interference with immunosuppression.

Familial mediterranean fever (FMF) is an inherited autoinflammatory disorder characterized by recurrent episodes of fever and painful inflammation involving the intra-abdominal organs, the lungs and the joints, which is highly prevalent in specific ethnic groups including the Iranians. We report a 12-year-old boy from Iran, with a clinical history of recurrent fever. Based on the suggestive clinical data, mutational analysis revealed the presence of the novel c.1945C>T heterozygous variant in exon 10, which leads to a leucine to phenylalanine change at position 649 of the protein. The mutation was inherited from the mother. This novel mutation lies in exon 10 of the MEFV gene, which encodes for a domain called B30.2-SPRY, located in the C-terminal region of the pyrin protein and contains the most frequent mutations associated with FMF. The present report expands the spectrum of MEFV gene mutations associated with FMF. The uniqueness of this study, compared with other published case reports, consists in the new mutation found in the MEFV gene. In fact, new mutations in this gene are of high interest, in order to better understand the role of this gene in autoinflammation.

Objective Sleep disturbances are frequently reported in Mowat-Wilson Syndrome (MWS). The current study aimed to evaluate clinical and video-polysomnographic (VPSG) characteristics of the sleep architecture and abnormal electroencephalogram (EEG) patterns during sleep in MWS. Methods Sixteen individuals with MWS (range 16 months–25 years), attending the Department of Child Neurology and Psychiatry of the University of Bologna, were included. The “Sleep Disturbances Scale for Children (SDSC)” questionnaire was administered to all parents of MWS patients, and all patients underwent a VPSG recording. Results The analysis of the SDSC questionnaire revealed disturbances mainly at the sleep–wake transition and in initiating and maintaining sleep. Evaluation of sleep structure in MWS patients showed a significant reduction of total sleep time, an increase of wake after sleep onset and arousal index as compared to normal controls. An EEG pattern characterized by slowing of background activity and poverty of physiological sleep characterisitcs was observed in all patients. Moreover, in patients aged >7 years, anteriorly predominant spike and waves were observed, markedly activated by sleep configuring a sub-continuous or continuous activity. Conclusion Our data (both clinical and VPSG) documented the presence of significant and clinically relevant sleep disturbances in MWS patients. Moreover, we identified a characteristic age-dependent sleep EEG pattern that could provide a new element to assist in the management of MWS.

SOX4, together with SOX11 and SOX12, forms group C of SRY-related (SOX) transcription factors. They play key roles, often in redundancy, in multiple developmental pathways, including neurogenesis and skeletogenesis. De novo SOX11 heterozygous mutations have been shown to cause intellectual disability, growth deficiency, and dysmorphic features compatible with mild Coffin-Siris syndrome. Using trio-based exome sequencing, we here identify de novo SOX4 heterozygous missense variants in four children who share developmental delay, intellectual disability, and mild facial and digital morphological abnormalities. SOX4 is highly expressed in areas of active neurogenesis in human fetuses, and sox4 knockdown in Xenopus embryos diminishes brain and whole-body size. The SOX4 variants cluster in the highly conserved, SOX family-specific HMG domain, but each alters a different residue. In silico tools predict that each variant affects a distinct structural feature of this DNA-binding domain, and functional assays demonstrate that these SOX4 proteins carrying these variants are unable to bind DNA in vitro and transactivate SOX reporter genes in cultured cells. These variants are not found in the gnomAD database of individuals with presumably normal development, but 12 other SOX4 HMG-domain missense variants are recorded and all demonstrate partial to full activity in the reporter assay. Taken together, these findings point to specific SOX4 HMG-domain missense variants as the cause of a characteristic human neurodevelopmental disorder associated with mild facial and digital dysmorphism.

The combination of febrile illness-induced encephalopathy and rhabdomyolysis has thus far only been described in disorders that affect cellular energy status. In the absence of specific metabolic abnormalities, diagnosis can be challenging.The objective of this study was to identify and characterise pathogenic variants in two individuals from unrelated families, both of whom presented clinically with a similar phenotype that included neurodevelopmental delay, febrile illness-induced encephalopathy and episodes of rhabdomyolysis, followed by developmental arrest, epilepsy and tetraplegia.Whole exome sequencing was used to identify pathogenic variants in the two individuals. Biochemical and cell biological analyses were performed on fibroblasts from these individuals and a yeast two-hybrid analysis was used to assess protein-protein interactions.Probands shared a homozygousOur study implicates a RAB11 pathway in the aetiology of the TRAPPC2L disorder and has implications for other TRAPP-related disorders with similar phenotypes.

Phospholipase A2-associated neurodegeneration (PLAN), a syndrome of Neurodegeneration with Brain Iron Accumulation (NBIA), is an autosomal recessive disorder caused by mutations in PLA2G6 gene. This gene encodes a calcium-independent group VI phospholipase A2 (iPLA-VI) critical in cell membrane homeostasis. PLAN syndrome encompasses a group of phenotypes with a different age of onset: classic infantile neuroaxonal dystrophy (INAD), atypical neuroaxonal dystrophy of childhood-onset (atypical NAD) and adult-onset PLA2G6-related dystonia-parkinsonism (PARK14). INAD is a severe progressive psychomotor disorder characterized by the presence of axonal spheroids throughout the central and peripheral nervous system. Here we report clinical, genetic and histopathological findings of an INAD consanguineous-family from Senegal. Sanger sequencing analysis revealed a new homozygous PLA2G6-mutation in the proband (c.1483C > T) and the co-segregation of the mutation in this family. Electron microscopy on skin biopsy showed degenerated axons confirming the phenotype. This study contributes to enrich the landscape of PLA2G6-associated INAD mutations and enforce the genotype-phenotype correlation.

The pace of discovery in the field of human genetics has increased exponentially in the last 30 years. We have witnessed the completion of the Human Genome Project, the identification of hundreds of disease-causing genes, and the dawn of genomic medicine (clinical care based on genomic information). Reduction of DNA sequencing costs, thanks to the so-called "next generation sequencing" technologies, is driving a shift towards the era of "personal genomes", but scientific as well as ethical challenges ahead are countless. We provide an overview on the classification of genetic tests, on informed consent procedures in the context of genetic counseling, and on specific ethical issues raised by the implementation of new DNA sequencing technologies.

Truncating mutations in PRNP have been associated with heterogeneous phenotypes ranging from chronic diarrhea and neuropathy to dementia, either rapidly or slowly progressive. We identified novel PRNP stop-codon mutations (p.Y163X, p.Y169X) in two Italian kindreds. Disease typically presented in the third or fourth decade with progressive autonomic failure and diarrhea. Moreover, one proband (p.Y163X) developed late cognitive decline, whereas some of his relatives presented with isolated cognitive and psychiatric symptoms. Our results strengthen the link between PRNP truncating mutations and systemic abnormal PrP deposition and support a wider application of PRNP screening to include unsolved cases of familial autonomic neuropathy.

Hereditary hearing loss (HHL) is a common disorder characterized by a huge genetic heterogeneity. The definition of a correct molecular diagnosis is essential for proper genetic counseling, recurrence risk estimation, and therapeutic options. From 20 to 40% of patients carry mutations in GJB2 gene, thus, in more than half of cases it is necessary to look for causative variants in the other genes so far identified (~100). In this light, the use of next-generation sequencing technologies has proved to be the best solution for mutational screening, even though it is not always conclusive. Here we describe a combined approach, based on targeted re-sequencing (TRS) of 96 HHL genes followed by high-density SNP arrays, aimed at the identification of the molecular causes of non-syndromic HHL (NSHL). This strategy has been applied to study 103 Italian unrelated cases, negative for mutations in GJB2, and led to the characterization of 31% of them (i.e., 37% of familial and 26.3% of sporadic cases). In particular, TRS revealed TECTA and ACTG1 genes as major players in the Italian population. Furthermore, two de novo missense variants in ACTG1 have been identified and investigated through protein modeling and molecular dynamics simulations, confirming their likely pathogenic effect. Among the selected patients analyzed by SNP arrays (negative to TRS, or with a single variant in a recessive gene) a molecular diagnosis was reached in ~36% of cases, highlighting the importance to look for large insertions/deletions. Moreover, copy number variants analysis led to the identification of the first case of uniparental disomy involving LOXHD1 gene. Overall, taking into account the contribution of GJB2, plus the results from TRS and SNP arrays, it was possible to reach a molecular diagnosis in ~51% of NSHL cases. These data proved the usefulness of a combined approach for the analysis of NSHL and for the definition of the epidemiological picture of HHL in the Italian population.

Neurofibromatosis type I, a genetic disorder due to mutations in the NF1 gene, is characterized by a high mutation rate (about 50% of the cases are de novo) but, with the exception of whole gene deletions associated with a more severe phenotype, no specific hotspots and few solid genotype/phenotype correlations. After retrospectively re-evaluating all NF1 gene variants found in the diagnostic activity, we studied 108 patients affected by neurofibromatosis type I who harbored mutations that had not been previously reported in the international databases, with the aim of analyzing their type and distribution along the gene and of correlating them with the phenotypic features of the affected patients. Out of the 108 previously unreported variants, 14 were inherited by one of the affected parents and 94 were de novo. Twenty-nine (26.9%) mutations were of uncertain significance, whereas 79 (73.2%) were predicted as pathogenic or probably pathogenic. No differential distribution in the exons or in the protein domains was observed and no statistically significant genotype/phenotype correlation was found, confirming previous evidences.

Loss of function mutations in PAK3 contribute to non-syndromic X-linked intellectual disability (NS-XLID) by affecting dendritic spine density and morphology. Linkage analysis in a three-generation family with affected males showing intellectual disability, agenesis of corpus callosum, cerebellar hypoplasia, microcephaly and ichthyosis, revealed a candidate disease locus in Xq21.33q24 encompassing over 280 genes. Subsequent to sequencing all coding exons of the X chromosome, we identified a single novel variant within the linkage region, affecting a conserved codon of PAK3. Biochemical studies showed that, similar to previous NS-XLID-associated lesions, the predicted amino acid substitution (Lys389Asn) abolished the kinase activity of PAK3. In addition, the introduced residue conferred a dominant negative function to the protein that drives the syndromic phenotype. Using a combination of in vitro and in vivo studies in zebrafish embryos we show that PAK3N389 escapes its physiologic degradation and is able to perturb MAPK signaling via an uncontrolled kinase-independent function, which in turn leads to alterations of cerebral and craniofacial structures in vivo. Our data expand the spectrum of phenotypes associated with PAK3 mutations, characterize a novel mechanism resulting in a dual molecular effect of the same mutation with a complex PAK3 functional deregulation, and provide evidence for a direct functional impact of aberrant PAK3 function on MAPK signaling.