Biomedical subjects

Charles Coutton

Publications and source records attributed to Charles Coutton.

3 recordsLinked to original sources

PubMed2026

A CCNA1 Missense Variant Associated With Chromatid Non-Disjunction in Abnormal-Headed Sperm and Male Infertility.

BACKGROUND: Macrozoospermia is a rare form of teratozoospermia characterized by tetraploids, large-headed spermatozoa with multiple flagella, usually caused by bi-allelic AURKC mutations. The etiology of atypical phenotypes with a lower proportion of large headed spermatozoa and single flagella however often remains unresolved. OBJECTIVE: To investigate the genetic cause of severe sperm-head abnormalities with moderate macrozoospermia without multiflagellated spermatozoa in a patient with repeated ICSI failure. An infertile male with three failed ICSI attempts underwent semen analysis, revealing complete teratozoospermia, including 25% macrocephalic spermatozoa. METHODS: Multi-probe FISH targeting chromosomes 13, 18, 21, X, Y assessed chromosomal segregation. Whole-exome sequencing (WES) was performed to identify a candidate variant associated with meiotic abnormalities. RESULTS: FISH analysis revealed a high proportion of spermatozoa with n (23) chromosomes and 2c DNA content, consistent with sister chromatid non-disjunction during meiosis II. WES identified a homozygous missense variation in CCNA1, coding for a protein described to be essential for meiotic progression and chromatin remodeling in male germ cells. DISCUSSION: The variant affects a highly conserved residue within a functional domain and is predicted to be deleterious. This study establishes the first clinical association between CCNA1 mutations and chromatid non-disjunction in human spermatogenesis. It highlights the limitations of current morphology-based diagnostic thresholds and supports cytogenetic and genomic assessment for severe teratozoospermia (especially head abnormalities) and ART failure. CONCLUSION: Expanding genetic screening panels to include CCNA1 may improve diagnostic precision and clinical management in atypical macrozoospermia cases.

ART failure↗

PubMed2026

35 Individuals With HUWE1-Related Neurodevelopmental Disorder and Suggested Clinical Evaluations.

HUWE1 (HECT, UBA, and WWE Domain Containing E3 Ubiquitin Protein Ligase1, OMIM 300697), located at Xp11.22, encodes a ubiquitin ligase that is highly conserved across species. Genetic variants in HUWE1 described in multiple independent studies cause X-linked intellectual disability, including in the patients identified by Juberg, Marsidi, and Brooks. This report describes 35 additional cases of individuals with variants in HUWE1 and suggested guidelines for clinical management. Our study includes several female cases, which have not been widely reported previously. Our findings confirm earlier reported clinical features including developmental delay, autism, hypotonia, short stature, and dysmorphic facial features as well as additional multisystemic findings. Intrauterine growth restriction (IUGR) and feeding difficulties were common in the neonatal period. It is notable that nearly all females had de novo variants, and males had de novo or inherited variants from clinically unaffected carrier mothers. Three genetic hotspots were identified in evolutionarily conserved regions of HUWE1 that have clinical impact. This report provides additional characterization of the spectrum of HUWE1-related neurodevelopmental disorder (HNDD).

Humans↗

PubMed2024

Microduplications of ARID1A and ARID1B cause a novel clinical and epigenetic distinct BAFopathy.

PURPOSE: ARID1A/ARID1B haploinsufficiency leads to Coffin-Siris syndrome, duplications of ARID1A lead to a distinct clinical syndrome, whilst ARID1B duplications have not yet been linked to a phenotype. METHODS: We collected patients with duplications encompassing ARID1A and ARID1B duplications. RESULTS: 16 ARID1A and 13 ARID1B duplication cases were included with duplication sizes ranging from 0.1 to 1.2 Mb (1-44 genes) for ARID1A and 0.9 to 10.3 Mb (2-101 genes) for ARID1B. Both groups shared features, with ARID1A patients having more severe intellectual disability, growth delay, and congenital anomalies. DNA methylation analysis showed that ARID1A patients had a specific methylation pattern in blood, which differed from controls and from patients with ARID1A or ARID1B loss-of-function variants. ARID1B patients appeared to have a distinct methylation pattern, similar to ARID1A duplication patients, but further research is needed to validate these results. Five cases with duplications including ARID1A or ARID1B initially annotated as duplications of uncertain significance were evaluated using PhenoScore and DNA methylation reanalysis, resulting in the reclassification of 2 ARID1A and 2 ARID1B duplications as pathogenic. CONCLUSION: Our findings reveal that ARID1B duplications manifest a clinical phenotype, and ARID1A duplications have a distinct episignature that overlaps with that of ARID1B duplications, providing further evidence for a distinct and emerging BAFopathy caused by whole-gene duplication rather than haploinsufficiency.

Humans↗