Pure partial monosomy 3p (3p25.3 → pter): prenatal diagnosis and array comparative genomic hybridization...

Area of Science:

• Prenatal diagnosis
• Human genetics
• Molecular cytogenetics

Background:

• Advanced maternal age and a history of intrauterine fetal demise prompted genetic evaluation.
• Prenatal diagnosis was pursued due to a suspected chromosomal abnormality.

Observation:

• Amniocentesis revealed a distal deletion on chromosome 3p.
• Array comparative genomic hybridization (aCGH) identified a 9.29-Mb deletion in the 3p26.3p25.3 region.
• Quantitative fluorescent polymerase chain reaction (QF-PCR) indicated paternal origin of the deletion.

Findings:

• The deletion encompassed several neurodevelopmental genes, including CHL1, CNTN4, CRBN, LRRN1, ITPR1, and SRGAP3.
• The deletion did not involve the congenital heart disease susceptibility locus.
• Post-termination examination of the fetus revealed dysmorphic features such as brachycephaly and hypertelorism.

Implications:

• aCGH and QF-PCR are valuable tools for characterizing de novo chromosomal aberrations detected prenatally.
• Understanding the specific deleted region and its associated genes aids in genetic counseling for parents.
• This case highlights the utility of molecular cytogenetics in diagnosing complex genetic conditions during pregnancy.