A fetus with Kabuki syndrome 2 detected by chromosomal microarray analysis

Area of Science:

• Genetics
• Prenatal Diagnosis
• Fetal Medicine

Background:

• Kabuki syndrome is a rare genetic disorder with diverse congenital anomalies.
• Current diagnosis relies on clinical signs and genetic testing, with no prior reports of fetal identification via CMA.
• Prenatal diagnosis often faces challenges with rare genetic conditions.

Observation:

• A fetus presented with growth retardation and cardiovascular abnormalities detected via ultrasonography.
• Non-invasive prenatal testing (NIPT) and G-banding karyotyping yielded normal results.
• Chromosomal microarray analysis (CMA) identified a 1.3 Mb deletion on the X chromosome (Xp11.3).

Findings:

• The deletion encompassed genes including KDM6A, DUSP21, MIR222, MIR221, and CXorf36, leading to a diagnosis of Kabuki syndrome 2.
• The same deletion was identified in the mother, indicating a potential inherited genetic factor.
• This marks the first reported case of Kabuki syndrome diagnosed prenatally using CMA.

Implications:

• CMA is a valuable tool for diagnosing Kabuki syndrome in fetuses with unexplained growth and developmental abnormalities.
• Integrating CMA into prenatal diagnostic workflows can improve early detection and management of rare genetic disorders.
• This case highlights the utility of CMA in identifying submicroscopic chromosomal deletions missed by conventional methods.