Prenatal Diagnosis and Molecular Cytogenetic Analyses of a de novo Deletion on Chromosome 4p16.3p15.33

Wolf-Hirschhorn syndrome (WHS) (OMIM 194190) is a contiguous gene syndrome with an estimated prevalence of around 1 in 50,000 births. The syndrome is caused by the deletion of a critical region (Wolf-Hirschhorn Syndrome Critical region-WHSCR) on chromosome 4p16.3. Its core features are typical facial gestalt, growth retardation, intellectual disability, developmental delay, and seizures. Prenatal diagnosis of WHS helps clinicians and parents make informed decisions about pregnancy management. In this research, a 31-year-old woman (gravida 1, para 0) underwent amniocentesis at 18 weeks gestation because of the short nasal bone of the fetus on prenatal ultrasound. Chromosomal microarray analysis (CMA) on uncultured amniocytes revealed a de novo 11.36-Mb deletion on chromosome 4p16.3p15.33, spanning from position 40 000 to 11 400 000 (hg19). After genetic counselling and being informed of the unfavorable prognosis, the parents decided to terminate the pregnancy. We provide a detailed description of a de novo 11.36-Mb deletion on chromosome 4p16.3p15.33 (Wolf-Hirschhorn syndrome). CMA has more advantages than karyotype analysis in detecting chromosomal microdeletions/microduplications. A combination of karyotype analysis, CMA, prenatal ultrasound, and genetic counseling is helpful for the prenatal diagnosis of chromosomal deletions/duplications.