Hypotonia, hypoventilation, impaired intellectual development, dysautonomia, epilepsy, and eye abnormalities (HIDEA) (OMIM #618493) is an autosomal recessive neurodevelopmental disorder caused by biallelic pathogenic variants in prolyl 4‐hydroxylase, transmembrane (P4HTM). This evidence concerns the gene P4HTM and hypotonia, hypoventilation, impaired intellectual development, dysautonomia, epilepsy, and eye abnormalities.