Recent case reports describe families with multiple affected children with megacystis microcolon intestinal hypoperistalsis syndrome, due to de novo disease‐causing variants in the ACTG2 gene, suggestive of gonadal mosaicism.36 Similarly, diagnostic exome sequencing in 13 families with known consanguinity indicated that over 38% of positive results were not autosomal recessive.37 One of the 11 couples tested who were known to be consanguineous each had a different missense variant in the BBS9 gene that was compound heterozygous in their affected fetus. The gene discussed is ACTG2; the disease is Megacystis.