MED13L-related intellectual disability: involvement of missense variants and delineation of the phenotype.

Molecular anomalies in MED13L, leading to haploinsufficiency, have been reported in patients with moderate to severe intellectual disability (ID) and distinct facial features, with or without congenital heart defects. Phenotype of the patients was referred to "MED13L haploinsufficiency syndrome." Missense variants in MED13L were already previously described to cause the MED13L-related syndrome, but only in a limited number of patients. Here we report 36 patients with MED13L molecular anomaly, recruited through an international collaboration between centers of expertise for developmental anomalies. All patients presented with intellectual disability and severe language impairment. Hypotonia, ataxia, and recognizable facial gestalt were frequent findings, but not congenital heart defects. We identified seven de novo missense variations, in addition to protein-truncating variants and intragenic deletions. Missense variants clustered in two mutation hot-spots, i.e., exons 15-17 and 25-31. We found that patients carrying missense mutations had more frequently epilepsy and showed a more severe phenotype. This study ascertains missense variations in MED13L as a cause for MED13L-related intellectual disability and improves the clinical delineation of the condition.

Genetic counselling difficulties and ethical implications of incidental findings from array-CGH: a 7-year national survey.

Microarray-based comparative genomic hybridization (aCGH) is commonly used in diagnosing patients with intellectual disability (ID) with or without congenital malformation. Because aCGH interrogates with the whole genome, there is a risk of being confronted with incidental findings (IF). In order to anticipate the ethical issues of IF with the generalization of new genome-wide analysis technologies, we questioned French clinicians and cytogeneticists about the situations they have faced regarding IF from aCGH. Sixty-five IF were reported. Forty corresponded to autosomal dominant diseases with incomplete penetrance, 7 to autosomal dominant diseases with complete penetrance, 14 to X-linked diseases, and 4 were heterozygotes for autosomal recessive diseases with a high prevalence of heterozygotes in the population. Therapeutic/preventive measures or genetic counselling could be argued for all cases except four. These four IF were intentionally not returned to the patients. Clinicians reported difficulties in returning the results in 29% of the cases, mainly when the question of IF had not been anticipated. Indeed, at the time of the investigation, only 48% of the clinicians used consents mentioning the risk of IF. With the emergence of new technologies, there is a need to report such national experiences; they show the importance of pre-test information on IF.

Molecular findings and clinical data in a cohort of 150 patients with anophthalmia/microphthalmia.

Anophthalmia and microphthalmia (AM) are the most severe malformations of the eye, corresponding respectively to reduced size or absent ocular globe. Wide genetic heterogeneity has been reported and different genes have been demonstrated to be causative of syndromic and non-syndromic forms of AM. We screened seven AM genes [GDF6 (growth differentiation factor 6), FOXE3 (forkhead box E3), OTX2 (orthodenticle protein homolog 2), PAX6 (paired box 6), RAX (retina and anterior neural fold homeobox), SOX2 (SRY sex determining region Y-box 2), and VSX2 (visual system homeobox 2 gene)] in a cohort of 150 patients with isolated or syndromic AM. The causative genetic defect was identified in 21% of the patients (32/150). Point mutations were identified by direct sequencing of these genes in 25 patients (13 in SOX2, 4 in RAX, 3 in OTX2, 2 in FOXE3, 1 in VSX2, 1 in PAX6, and 1 in GDF6). In addition eight gene deletions (five SOX2, two OTX2 and one RAX) were identified using a semi-quantitative multiplex polymerase chain reaction (PCR) [quantitative multiplex PCR amplification of short fluorescent fragments (QMPSF)]. The causative genetic defect was identified in 21% of the patients. This result contributes to our knowledge of the molecular basis of AM, and will facilitate accurate genetic counselling.

Trisomy 7 mosaicism prenatally misdiagnosed and maternal uniparental disomy in a child with pigmentary mosaicism and Russell- Silver syndrome.

Prenatal diagnosis of true mosaic trisomy 7 is rare in amniotic fluid and can be misinterpreted as pseudomosaic. The phenotype is highly variable and may be modified by a maternal uniparental disomy of chromosome 7 leading to mild Russell-Silver syndrome (RSS). We report here the third postnatal case of mosaic trisomy 7 with maternal uniparental disomy of chromosome 7 in a boy presenting a mild RSS. Fetal karyotype performed in amniocentesis for intrauterine growth retardation was considered normal. Mosaic trisomy 7 was diagnosed after birth, on fibroblasts karyotype performed for blaschkolinear pigmentary skin anomalies and failure to thrive. Maternal uniparental disomy of chromosome 7 was observed in blood sample. Retrospectively, trisomic 7 cells were identified in one prenatal long-term flask culture revealing a prenatal diagnosis failure. This report emphasizes the difficulty of assessing fetal mosaicism and distinguishing it from pseudomosaicism in cultured amniocytes. It is important to search for uniparental disomy as an indirect clue of trisomy 7 mosaicism and a major prognosis element. Although there are only few prenatal informative cases, detection of trisomy 7 in amniocentesis appears to be associated with a relatively good outcome when maternal uniparental disomy has been ruled out.

[Genetics and orthopedics: genetic implications of congenital limb abnormalities]. / Génétique et orthopédie: gènes impliqués dans les malformations congénitales des membres.

Limb malformations are frequent. These malformations are isolated or associated with anomalies of other developmental fields and accurate diagnostic is essential for prognosis evaluation, treatment and genetic counseling. Animal embryology and molecular biology techniques, have given us a better understanding of the processes of growth and patterning of the limb buds. The key genes that are involved in these processes have been identified and their interactions recognized. Human genetics has been able to identify, or at least localize, several genes implicated in limb development. We here review the present knowledge on these genes and their mutations responsible for limb anomalies.

Blau syndrome of granulomatous arthritis, iritis, and skin rash: a new family and review of the literature.

Blau syndrome (MK186580) comprises granulomatous arthritis, iritis, and skin rash, and is an autosomal-dominant trait with variable expressivity. So far it was described in 5 families. We report on a sixth family with severe progression of eye involvement and discuss the nosology with similar diseases, such as early-infantile sarcoidosis.

Fryns syndrome and erupted teeth in a 24-weeks-old fetus.

We describe a 24-weeks-old fetus with Fryns' syndrome (FS) and two erupted incisors. The present observations is another example of prenatal diagnosis of FS, based on ultrasonographically detected hernia diaphragmatica and cystic hygroma. It also adds an hitherto non described finding in FS. The presence of prenatally erupted teeth without any similar family history is discussed.

Pulmonary hypertension of the newborn and urogenital anomalies in two male siblings: a new family with misalignment of pulmonary vessels.

The association of pelvi-ureteric junction obstruction (PUJO) and rapidly fatal persistent pulmonary hypertension of the newborn (PPHN) has been observed in two male siblings. PUJO was also observed in a maternal uncle, whose daughter suffered from vesico-ureteral reflux (VUR). In both patients, histopathologic study of the lungs showed misalignment of pulmonary veins (MAPV), which is a rare autosomal recessive condition leading to severe PPHN and death within the neonatal period. It has occasionally been described associated with PUJO. The authors point out that: i: MAPV has to be carefully searched in case of PPHN; ii: PUJO could be an important finding associated with MAPV, and the only prenatal indication of this lethal condition.

[Dyggve-Melchior-Clausen syndrome: differential diagnosis of mucopolysaccharidosis type IV or Morquio disease]. / Le syndrome de Dyggve-Melchior-Clausen: diagnostic différentiel de la mucopolysaccharidose de type IV ou maladie de Morquio.

UNLABELLED: Dyggve-Melchior-Clausen syndrome (DMCS) is an autosomal recessive skeletal dysplasia. Clinical and radiological similarities with Morquio's syndrome can initially lead wrongly to this diagnosis. CASE REPORT: A nine-year-old boy had mental retardation and progressive postnatal dwarfism. Platyspondyly and dysplastic epiphyses and metaphyses resembled those of Morquio's disease; however, clinical and radiological data led to the diagnosis of DMCS. CONCLUSION: Clinical and paraclinical features allowing the differentiation of Morquio's syndrome and DMCS are discussed. Initial clinical presentation may be similar, but the intellectual prognosis is different.