HDR syndrome (HDRS), also known as Barakat syndrome, is a heterogeneous disorder characterized by the triad of Hypoparathyroidism (H), nerve Deafness (D) and/or Renal disease (R). Variable clinical features include hypogonadotrophic hypogonadism, polycystic ovaries, congenital heart disease, retinitis pigmentosa, and cognitive disability (Barakat et al., 2018).

This syndrome has characteristics of holoprosencephaly, predominantly radial limb deficiency (absent thumbs, phocomelia), heart defects, kidney malformations and absence of gallbladder. It has been described in two families (with at least seven affected persons). Variable manifestations include vertebral anomalies, cleft lip/palate, microphthalmia, absent nose, dysplastic ears, hearing loss, colobomas of the iris and retina and/or bifid uvula. Inheritance is likely to be autosomal dominant with variable expressivity.