The HHAT-related multiple congenital anomaly syndrome is a rare genetic disorder with seven affected individuals from three unrelated families reported till date.

The classical features of this multiple congenital anomaly syndrome are holoprosencephaly, agenesis of corpus callosum, intellectual disability, cerebellar vermis hypoplasia, microphthalmia-anophthalmia, short stature, skeletal dysplasia, sex reversal and elevated creatine kinase.

This condition is inherited in an autosomal recessive manner with report of three homozygous variants in the HHAT (Hedgehog acyl-transferase) gene. The affected individuals inherited the biallelic variants disease causing variants from their unaffected (heterozygous carriers) parents.