First Cornelia de Lange Syndrome Type 4 Caused by the Gonadal Mosaicism of RAD21 Deletion.
Yanchuan Xie, Dongyan Li, Wensheng Li et al.
✦ AI-curated · Sources linked
Case in brief
This report describes two siblings from a Chinese family diagnosed with Cornelia de Lange syndrome Type 4, characterized by dysmorphic facial features, cleft palate, spina bifida occulta, and limb abnormalities. Whole-genome sequencing revealed a heterozygous deletion of the RAD21 gene. Genetic analysis indicated that the deletion likely resulted from maternal gonadal mosaicism, as both parents' blood samples were normal.
What made this case unusual
The case highlights the occurrence of Cornelia de Lange syndrome Type 4 due to maternal gonadal mosaicism, a rare genetic phenomenon that complicates inheritance patterns.
Diagnostic / clinical pearl
Clinicians should consider gonadal mosaicism in cases of genetic disorders when both parents exhibit normal genetic testing results but siblings present with significant phenotypic features.
Why it matters
Understanding the implications of gonadal mosaicism is crucial for accurate genetic counseling and risk assessment in families with inherited conditions.