Genotype-Phenotype Correlations and Sex Differences in ZC4H2-Associated Rare Disorder.

Area of Science:

• Genetics
• Neurology
• Rare Diseases

Background:

• ZC4H2-associated rare disorder (ZARD) is a condition caused by variations in the ZC4H2 gene on the X chromosome, impacting neural development.
• Symptoms of ZARD are highly variable and may differ between males and females.

Purpose of the Study:

• To investigate genotype-phenotype correlations in ZARD.
• To identify sex-based differences in ZARD presentation and inheritance patterns.

Main Methods:

• Prospective natural history study of 40 individuals with ZARD.
• Standardized interviews, developmental assessments, and neurological examinations every six months for two years.
• Statistical analyses including Fisher exact, maximum likelihood χ2, and Mann-Whitney tests.

Main Results:

• Males more often inherited ZC4H2 variations maternally, while females had de novo variations (P < 0.001).
• Females showed higher incidence of contractures, arthrogryposis multiplex congenita, spasticity, and lower limb muscle atrophy.
• Males were more prone to seizures, intermittent pain, severe vision impairment, dysphagia for solids, and generalized muscle atrophy.

Conclusions:

• ZARD exhibits significant symptom overlap between sexes, but distinct sex-specific commonalities exist.
• Further research is required to elucidate the impact of specific pathogenic variation types on ZARD phenotype.