Prenatal diagnosis of a fetus with harlequin ichthyosis caused by novel splice-site mutation in ABCA12 gene / 中华围产医学杂志

ABSTRACT

This article reported a rare case of harlequin ichthyosis which was indicated with multiple structural abnormalities by prenatal ultrasound and diagnosed by trio-based whole-exome sequencing (Trio-WES). Prenatal diagnosis was performed because the ultrasound at 24 +4 gestational weeks revealed the fetus presenting with eclabium, flattened nose, short mandible, small auricle and abnormal posture of the toes. Copy number variation sequencing (CNV-seq) showed no chromosome aneuploidy or pathogenic copy number variants over 100 kb in the fetal or parental samples. Trio-WES showed that the fetus carried two heterozygous mutations, c.2593-1G>A and c.7444C>T in ABCA12. Sanger sequencing confirmed that c.2593-1G>A, a previously unreported variant, was paternally inherited and c.7444C>T was maternally inherited. Both parents had normal phenotype. The fetus was finally diagnosed with harlequin ichthyosis. After prenatal counseling, the parents made an informed choice to terminate the pregnancy at 28 +4 gestational weeks. The stillborn fetus showed multiple malformations The variants in this case expand the spectrum of variants in ABCA12 gene.