Hedgehog acyl-transferase-related multiple congenital anomalies: Report of an additional family and delineation of the syndrome

This study includes previous reports of four affected individuals from two unrelated families with hedgehog acyl-transferase (HHAT)-related multiple congenital anomaly syndrome. Microcephaly, small cerebellar vermis, holoprosencephaly, agenesis of corpus callosum, intellectual disability, short stature, skeletal dysplasia, microphthalmia–anophthalmia, and sex reversal constitute the phenotypic spectrum of this condition with variable expression. We report an additional family with three affected conceptuses: two abortuses and one living proband. We did proband–parents trio exome sequencing and identified a biallelic in-frame deletion c.365_367del; (p.Thr122del) in exon 5 of HHAT. With this report, we delineate the phenotype and allelic heterogeneity of the HHAT-related multiple congenital anomaly syndrome.