A novel homozygous variant in JAM3 gene causing hemorrhagic destruction of the brain, subependymal calcification, and congenital cataracts (HDBSCC) with neonatal onset.

BACKGROUND: JAM3 gene, located on human chromosome 11q25, encodes a member of the junctional adhesion molecule (JAM) family. Mutations of this gene are associated with hemorrhagic destruction of the brain, subependymal calcification, and congenital cataracts (HDBSCC). CASE REPORT: Herein, we present a newborn male with a prenatal suspicion of bilateral cataracts but without fetal ultrasound findings of cortical malformations. He was postnatally diagnosed with a clinical picture of HDBSCC and Early-onset Developmental and Epileptic Encephalopathy (DEE), associated to a homozygous variant of JAM3 gene. CONCLUSION: Identification of this variant in affected individuals has implications for perinatal and postnatal management and genetic counseling. To the best of our knowledge, this is the first case reported of a child with a JAM3 variant in Italy, from a different ethnic background than the other reported children until now (Saudi Arabian, Turkish, Afghani, and Moroccan origin). JAM3 screening could be requested in prenatal diagnosis of fetal congenital cataracts and included in Next-Generation DNA Sequencing panels.

Variable expressivity of a familial 1.9 Mb microdeletion in 3q28 leading to haploinsufficiency of TP63: Refinement of the critical region for a new microdeletion phenotype.

We report on a 3-year-old male with intellectual disability (ID), characteristic facial features, polydactyly and epilepsy carrying a paternally inherited 3q28 deletion of 1.9 Mb. The father, carrying the same deletion, presents with cleft palate, nail dystrophy and learning difficulties. The deleted region in this family is one of the smallest so far reported among genomic deletions affecting 3q27-3q28 for which some phenotypic descriptions are available. In particular, since the phenotype of our proband is strikingly similar to that previously described in a patient with a 9.3 Mb deletion, the deletion identified in this report contributes to the definition of the molecular boundaries of a genomic region responsible for a distinct clinical phenotype. Within the deleted interval there are 9 annotated genes, including TP63. Gain of function mutations of TP63 are known to be responsible for a group of conditions with distal limb and ectodermal involvement, such as ADULT, EEC, LMS, and SHFM4 syndromes. Interestingly, our cases demonstrate a milder phenotypic effect for loss of function of this gene.

Unique genomic profile associated with pediatric uveal melanoma.

PURPOSE: To determine genetic features of a pediatric uveal melanoma in a 6-year-old girl by array-based comparative genomic hybridization (a-CGH) and assess prognosis, and to search for constitutional copy number variations (CNVs) encompassing oncosuppressor genes. METHODS: High-resolution a-CGH was performed on genomic DNA from cancer cells and from peripheral blood cells. Histopathology and clinical staging of the tumor were simultaneously assessed. RESULTS: Array-based CGH revealed no CNVs on tumor cells associated with poor prognosis; namely, no monosomy 3, losses of 1p, 6q, or 8p, and no gains of 8q. A unique genomic profile was observed, consisting mainly of partial terminal duplications affecting chromosomes 1, 4, 5, 9, 10, 11, 16, and 19, and complete trisomy of chromosomes 6, 7, and 20. The nonmetastatic tumor had predominantly epithelioid histology. No constitutional CNVs encompassing oncosuppressor genes were detected. CONCLUSIONS: We report a very rare uveal melanoma characterized by low-risk genomic profile and poor prognostic histologic and clinical features. The child is relapse-free at 1-year follow-up. The unusual CNVs detected by a-CGH suggest specific pathogenic mechanisms.

Novel de novo heterozygous loss-of-function variants in MED13L and further delineation of the MED13L haploinsufficiency syndrome.

MED13L haploinsufficiency has recently been described as responsible for syndromic intellectual disability. We planned a search for causative gene variants in seven subjects with intellectual disability and overlapping dysmorphic facial features such as bulbous nasal tip, short mouth and straight eyebrows. We found two de novo frameshift variants in MED13L, consisting in single-nucleotide deletion (c.3765delC) and duplication (c.607dupT). A de novo nonsense variant (c.4420A>T) in MED13L was detected in a further subject in the course of routine whole-exome sequencing. By analyzing the clinical data of our patients along with those recently described in the literature, we confirm that there is a common, recognizable phenotype associated with MED13L haploinsufficiency, which includes intellectual disability and a distinctive facial appearance. Congenital heart diseases are found in some subjects with various degree of severity. Our observation of cleft palate, ataxia, epilepsy and childhood leukemia observed in single cases broadens the known clinical spectrum. Haploinsufficiency for MED13L should be considered in the differential diagnosis of the 1p36 microdeletion syndrome, due to overlapping dysmorphic facial features in some patients. The introduction of massive parallel-sequencing techniques into clinical practice is expected to allow for detection of other causative point variants in MED13L. Analysis of genomic data in connection with deep clinical evaluation of patients could elucidate genetic heterogeneity of the MED13L haploinsufficiency phenotype.