[Application of chromosome microarray analysis for fetuses with multicystic dysplastic kidney]

Area of Science:

• Medical Genetics
• Prenatal Diagnosis
• Developmental Biology

Background:

• Multicystic dysplastic kidney (MCDK) is a common congenital kidney malformation.
• The genetic causes of MCDK are not fully understood.
• Conventional cytogenetic techniques have limitations in detecting submicroscopic chromosomal abnormalities.

Purpose of the Study:

• To investigate the genetic etiology of fetuses diagnosed with MCDK.
• To evaluate the utility of chromosome microarray analysis (CMA) in identifying pathogenic copy number variations (CNVs) in MCDK cases.
• To determine the detection rate of genetic abnormalities in fetuses with MCDK using CMA.

Main Methods:

• Seventy-two fetuses with MCDK were analyzed.
• Conventional cytogenetic techniques were initially employed.
• Thirty fetuses with normal karyotypes underwent CMA using Affymetrix CytoScan HD arrays.

Main Results:

• Conventional cytogenetics identified chromosomal aberrations in 4.2% of cases.
• CMA detected pathogenic CNVs in 16.7% of fetuses with MCDK.
• Identified CNVs included 17q12 microdeletion syndrome, Williams-Beuren syndrome, and novel imbalances at 4q35.2, 22q13.33, and 1p33.

Conclusions:

• CMA significantly enhances prenatal diagnosis by detecting submicroscopic imbalances missed by conventional methods.
• The study confirms an association between MCDK and 17q12 microdeletion syndrome and Williams-Beuren syndrome.
• Specific genes (PEX26, FKBP6, TUBGCP6, ALG12, CYP4A11) are implicated as potential causative factors for MCDK.