Small Complex Rearrangement in -Related Axonal Neuropathy.

Background: Autosomal recessive inherited pathogenetic variants in the histidine triad nucleotide-binding protein 1 () gene are responsible for an axonal Charcot-Marie-Tooth neuropathy associated with neuromyotonia, a phenomenon resulting from peripheral nerve hyperexcitability that causes a spontaneous muscle activity such as persistent muscle contraction, impaired relaxation and myokymias.

Methods: Herein, we describe two brothers in whom biallelic variants were identified following a multidisciplinary approach.

Results: The younger brother came to our attention for clinical evaluation of moderate intellectual disability, language developmental delay, and some behavioral issues.

Further evidence supporting the role of GTDC1 in glycine metabolism and neurodevelopmental disorders.

Copy number variants (CNVs) represent the genetic cause of about 15-20% of neurodevelopmental disorders (NDDs). We identified a ~67 kb de novo intragenic deletion on chromosome 2q22.3 in a female individual showing a developmental encephalopathy characterised by epilepsy, severe intellectual disability, speech delay, microcephaly, and thin corpus callosum with facial dysmorphisms.

Case Report: Decrypting an interchromosomal insertion associated with Marfan's syndrome: how optical genome mapping emphasizes the morbid burden of copy-neutral variants.

Optical genome mapping (OGM), which allows analysis of ultra-high molecular weight (UHMW) DNA molecules, represents a response to the restriction created by short-read next-generation-sequencing, even in cases where the causative variant is a neutral copy-number-variant insensitive to quantitative investigations. This study aimed to provide a molecular diagnosis to a boy with Marfan syndrome (MFS) and intellectual disability (ID) carrying a translocation involving chromosomes 3, 4, and 13 and a 1.7 Mb deletion at the breakpoint of chromosome 3.

Consensus recommendations on counselling in Phelan-McDermid syndrome, with special attention to recurrence risk and to ring chromosome 22.

This paper focuses on genetic counselling in Phelan-McDermid syndrome (PMS), a rare neurodevelopmental disorder caused by a deletion 22q13.3 or a pathogenic variant in SHANK3. It is one of a series of papers written by the European PMS consortium as a consensus guideline.