Finger creases lend a hand in Kabuki syndrome.

International audienceKabuki syndrome (KS) is a rare syndrome associating malformations with intellectual deficiency and numerous visceral, orthopedic, endocrinological, immune and autoimmune complications. The early establishment of a diagnostic of KS leads to better care of the patients and therefore prevents complications such as perception deafness, severe complications of auto-immune diseases or obesity. However, the diagnosis of KS remains difficult because based on the appreciation of facial features combined with other highly variable features. We describe a novel sign, namely the attenuation and/or congenital absence of the IPD crease of the third and fourth fingers associated with limitation of flexion of the corresponding joints, which seems to be specific of KS and could help the clinician to diagnose KS

Clinical spectrum of MTOR-related hypomelanosis of Ito with neurodevelopmental abnormalities.

PURPOSE: Hypomelanosis of Ito (HI) is a skin marker of somatic mosaicism. Mosaic MTOR pathogenic variants have been reported in HI with brain overgrowth. We sought to delineate further the pigmentary skin phenotype and clinical spectrum of neurodevelopmental manifestations of MTOR-related HI. METHODS: From two cohorts totaling 71 patients with pigmentary mosaicism, we identified 14 patients with Blaschko-linear and one with flag-like pigmentation abnormalities, psychomotor impairment or seizures, and a postzygotic MTOR variant in skin. Patient records, including brain magnetic resonance image (MRI) were reviewed. Immunostaining (n = 3) for melanocyte markers and ultrastructural studies (n = 2) were performed on skin biopsies. RESULTS: MTOR variants were present in skin, but absent from blood in half of cases. In a patient (p.[Glu2419Lys] variant), phosphorylation of p70S6K was constitutively increased. In hypopigmented skin of two patients, we found a decrease in stage 4 melanosomes in melanocytes and keratinocytes. Most patients (80%) had macrocephaly or (hemi)megalencephaly on MRI. CONCLUSION: MTOR-related HI is a recognizable neurocutaneous phenotype of patterned dyspigmentation, epilepsy, intellectual deficiency, and brain overgrowth, and a distinct subtype of hypomelanosis related to somatic mosaicism. Hypopigmentation may be due to a defect in melanogenesis, through mTORC1 activation, similar to hypochromic patches in tuberous sclerosis complex

A Solve-RD ClinVar-based reanalysis of 1522 index cases from ERN-ITHACA reveals common pitfalls and misinterpretations in exome sequencing

Purpose Within the Solve-RD project (https://solve-rd.eu/), the European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies aimed to investigate whether a reanalysis of exomes from unsolved cases based on ClinVar annotations could establish additional diagnoses. We present the results of the “ClinVar low-hanging fruit” reanalysis, reasons for the failure of previous analyses, and lessons learned. Methods Data from the first 3576 exomes (1522 probands and 2054 relatives) collected from European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies was reanalyzed by the Solve-RD consortium by evaluating for the presence of single-nucleotide variant, and small insertions and deletions already reported as (likely) pathogenic in ClinVar. Variants were filtered according to frequency, genotype, and mode of inheritance and reinterpreted. Results We identified causal variants in 59 cases (3.9%), 50 of them also raised by other approaches and 9 leading to new diagnoses, highlighting interpretation challenges: variants in genes not known to be involved in human disease at the time of the first analysis, misleading genotypes, or variants undetected by local pipelines (variants in off-target regions, low quality filters, low allelic balance, or high frequency). Conclusion The “ClinVar low-hanging fruit” analysis represents an effective, fast, and easy approach to recover causal variants from exome sequencing data, herewith contributing to the reduction of the diagnostic deadlock

Caractérisation de microremaniements chromosomiques dans des troubles autistiques syndromiques par hybridation génomique comparative sur puces à ADN

PARIS6-Bibl.Pitié-Salpêtrie (751132101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Mortality in patients with alpha-mannosidosis: a review of patients’ data and the literature

Abstract Background Alpha-mannosidosis is a rare autosomal recessive lysosomal storage disorder (LSD) caused by reduced activity of alpha-mannosidase. Clinical manifestations include skeletal dysmorphism, mental impairment, hearing loss and recurrent infections. The severe type of the disease leads to early childhood death, while patients with milder forms can live into adulthood. There are no mortality studies to date. This study aimed to investigate the age at death and the causes of death of patients with alpha-mannosidosis who had not received disease-modifying treatment. Methods Clinicians and LSD patient organisations (POs) from 33 countries were invited to complete a questionnaire between April–May 2021. Cause of death and age at death was available for 15 patients. A literature review identified seven deceased patients that met the inclusion criteria. Results Median age at death for patients reported by clinicians/POs was 45 years (mean 40.3 ± 13.2, range 18–56, n = 15); 53% were female. One death occurred during the patient’s second decade of life, and 14 out of 15 deaths (93.3%) during or after the patients’ third decade, including four (26.7%) during their sixth decade. Median age at death for patients identified from the literature was 4.3 years (mean 15.7 ± 17.0, range 2.2–41, n = 7); two were female. Four of the seven patients (57.1%) died within the first decade of life. Seven of 15 deaths (46.7%) reported by clinicians/POs were recorded as pneumonia and three (20.0%) as cancer. Other causes of death included acute renal failure due to sepsis after intestinal perforation, decrease of red blood cells of unknown origin, kidney failure with systemic lupus erythematosus, aortic valve insufficiency leading to heart failure, and dehydration due to catatonia. Three out of seven causes of death (42.9%) reported in the literature were associated with septicaemia, two (28.6%) with respiratory failure and one to pneumonia following aspiration. Conclusions This study suggests that pneumonia has been the primary cause of death during recent decades in untreated patients with alpha-mannosidosis, followed by cancer. Determining the causes of mortality and life expectancy in these patients is crucial to further improve our understanding of the natural history of alpha-mannosidosis

Xq25 duplications encompassing GRIA3 and STAG2 genes in two families convey recognizable X-linked intellectual disability with distinctive facial appearance.

International audienceWe report here on two patients with Xq25 duplication encompassing GRIA3 gene, encoding glutamate receptor, ionotropic, AMPA subunit 3. The first case of Xq25 duplication was identified using genome-wide array comparative genomic hybridization (array-CGH) in a 24-year-old patient with syndromic intellectual disability. Based on similar facial features, we clinically suspected a second case of Xq25 duplication in a 4-year-old boy with intellectual disabilty. This duplication was confirmed by multiplex ligation-dependent probe amplification (MLPA) of the GRIA3 gene, as well as by fluorescence in situ hybridization (FISH) and further refined by array-CGH. We suggest that Xq25 duplication is responsible for a novel clinically recognizable X-linked intellectual disability. Finally, the review of so far published Xq25 duplications support, in addition to the role of GRIA3 gene, a potential contribution of the duplication of STAG2 (Stromal Antigen 2) gene coding for the subunit SA1 of the cohesin complex in the clinical phenotype

Complementarity of electrophoretic, mass spectrometric, and gene sequencing techniques for the diagnosis and characterization of congenital disorders of glycosylation

International audienceCongenital disorders of glycosylation (CDG) are rare autosomal genetic diseases affecting the glycosylation of proteins and lipids. Since CDG-related clinical symptoms are classically extremely variable and nonspecific, a combination of electrophoretic, mass spectrometric, and gene sequencing techniques is often mandatory for obtaining a definitive CDG diagnosis, as well as identifying causative gene mutations and deciphering the underlying biochemical mechanisms. Here, we illustrate the potential of integrating data from capillary electrophoresis of transferrin, two-dimensional electrophoresis of N- and O-glycoproteins, mass spectrometry analyses of total serum N-linked glycans and mucin core1 O-glycosylated apolipoprotein C-III for the determination of various culprit CDG gene mutations. "Step-by-step" diagnosis pathways of four particular and new CDG cases, including MGAT2-CDG, ATP6V0A2-CDG, SLC35A2-CDG, and SLC35A3-CDG, are described as illustrative examples

Brief report: 11p15 imprinting center region 1 loss of methylation is a common and specific cause of typical Russell-Silver syndrome: Clinical scoring system and epigenetic-phenotypic correlations

Context: Russell-Silver syndrome (RSS), characterized by intrauterine and postnatal growth retardation, dysmorphic features, and frequent body asymmetry, spares cranial growth. Maternal uniparental disomy for chromosome 7 (mUPD7) is found in 5-10% of cases. We identified loss of methylation (LOM) of 11p15 Imprinting Center Region 1 (ICR1) domain (including IGF-II) as a mechanism leading to RSS. Objective: The aim was to screen for 11p15 epimutation and mUPD7 in RSS and non-RSS small-for-gestational-age (SGA) patients and identify epigenetic-phenotypic correlations. Studied Population and Methods: A total of 127 SGA patients were analyzed. Clinical diagnosis of RSS was established when the criterion of being SGA was associated with at least three of five criteria: postnatal growth retardation, relative macrocephaly, prominent forehead, body asymmetry, and feeding difficulties. Serum IGF-II was evaluated for 82 patients. Results: Of the 127 SGA patients, 58 were diagnosed with RSS; 37 of these (63.8%) displayed partial LOM of the 11p15 ICR1 domain, and three (5.2%) had mUPD7. No molecular abnormalities were found in the non-RSS SGA group (n = 69). Birth weight, birth length, and postnatal body mass index (BMI) were lower in the abnormal 11p15 RSS group (ab-ICR1-RSS) than in the normal 11p15 RSS group [-3.4 vs. -2.6 SD score (SDS), -4.4 vs. -3.4 SDS, and -2.5 vs. -1.6 SDS, respectively; P < 0.05]. Among RSS patients, prominent forehead, relative macrocephaly, body asymmetry, and low BMI were significantly associated with ICR1 LOM. All ab-ICR1-RSS patients had at least four of five criteria of the scoring system. Postnatal IGF-II levels were within normal values. Conclusion: The 11p15 ICR1 epimutation is a major, specific cause of RSS exhibiting failure to thrive. We propose a clinical scoring system (including a BMI < -2 SDS), highly predictive of 11p15 ICR1 LOM, for the diagnosis of RSS. Copyright © 2007 by The Endocrine Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe