Objective: To analyze ultrasonographic finding in fetuses with Wolf-Hirschhorn syndrome (WHS) and refine the critical region on chromosome 4p16.3 for WHS-associated fetal growth retardation (FGR).
Methods: In total 2262 fetuses with abnormal ultrasonographic findings who underwent prenatal karyotyping and chromosomal microarray analysis were reviewed. WHS-associated 4p deletions detected in these fetuses were compared, and prenatal ultrasound findings in such fetuses were summarized. Meanwhile, WHS cases with prenatal ultrasound findings and isolated 4p deletions in previous studies were included for further analysis. An analysis of smallest region of overlap (SRO) among discrepant 4p deletions in these cases above was performed to define a critical region for FGR.
Results: 4p deletions were detected in 10 of the 2262 fetuses and 5.0% of the 202 fetuses with FGR. Combined with 80 WHS cases from previous studies, the most common prenatal ultrasound finding was FGR, which yielded a frequency of 76.7%. In addition, a SRO spanning approximately 419 kb (genomic position: 1.32-1.74 Mb) on chromosome 4p16.3 was discovered by comparing the unusual 4p deletions among the 10 fetuses. The region contained seven protein-coding genes, including TACC3, SLBP, TMEM129, FAM53A, MAEA, UVSSA and CRIPAK.
Conclusion: For fetuses with WHS, the most common prenatal ultrasound phenotype was FGR. A region between 1.32 Mb to 1.74 Mb from the telomere on chromosome 4p16.3 is critical for WHS-associated FGR, for which TACC3 and SLBP are the candidate genes.