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).

Waardenburg syndrome type I (WS1) is an auditory-pigmentary disorder comprising congenital sensorineural hearing loss and pigmentary disturbances of the iris, hair, and skin along with dystopia canthorum (lateral displacement of the inner canthi). The hearing loss in WS1, observed in approximately 60% of affected individuals, is congenital, typically non-progressive, either unilateral or bilateral, and sensorineural. Most commonly, hearing loss in WS1 is bilateral and profound (>100 dB). The majority of individuals with WS1 have either a white forelock or early graying of the scalp hair before age 30 years. The classic white forelock observed in approximately 45% of individuals is the most common hair pigmentation anomaly seen in WS1. Affected individuals may have complete heterochromia iridium, partial/segmental heterochromia, or hypoplastic or brilliant blue irides. Congenital leukoderma is frequently seen on the face, trunk, or limbs.

Spondylocostal dysostosis-anal and genitourinary malformations syndrome is characterized by the association of spondylocostal dysostosis with anal and genitourinary malformations (anal atresia and agenesis of external and internal genitalia). To date, only four cases have been described in the literature. Autosomal recessive inheritance has been suggested.

Müllerian aplasia and hyperandrogenism is a condition that affects the reproductive system in females. This condition is caused by abnormal development of the Müllerian ducts, which are structures in the embryo that develop into the uterus, fallopian tubes, cervix, and the upper part of the vagina. Individuals with Müllerian aplasia and hyperandrogenism typically have an underdeveloped or absent uterus and may also have abnormalities of other reproductive organs. Women with this condition have normal female external genitalia, and they develop breasts and pubic hair normally at puberty; however, they do not begin menstruation by age 16 (primary amenorrhea) and will likely never have a menstrual period. Affected women are unable to have children (infertile).\n\nWomen with Müllerian aplasia and hyperandrogenism have higher-than-normal levels of male sex hormones called androgens in their blood (hyperandrogenism), which can cause acne and excessive facial hair (facial hirsutism). Kidney abnormalities may be present in some affected individuals.

17q12 recurrent deletion syndrome is characterized by variable combinations of the three following findings: structural or functional abnormalities of the kidney and urinary tract, maturity-onset diabetes of the young type 5 (MODY5), and neurodevelopmental or neuropsychiatric disorders (e.g., developmental delay, intellectual disability, autism spectrum disorder [ASD], attention-deficit/hyperactivity disorder [ADHD], schizophrenia, anxiety, and bipolar disorder). Using a method of data analysis that avoids ascertainment bias, the authors determined that multicystic kidneys and other structural and functional kidney anomalies occur in 85%-90% of affected individuals, MODY5 in approximately 40%, and some degree of developmental delay or learning disability in approximately 50%. MODY5 is most often diagnosed before age 25 years (range: age 10-50 years).

Mayer-Rokitansky-Kuster-Hauser syndrome (MRKH) is characterized by uterovaginal atresia in an otherwise phenotypically normal female with a normal 46,XX karyotype. Anomalies of the genital tract range from upper vaginal atresia to total mullerian agenesis with urinary tract abnormalities. It has an incidence of approximately 1 in 5,000 newborn girls (Cheroki et al., 2006). The abnormality of sexual development in MRKH syndrome is the same as that in the MURCS association (601076), in which cervicothoracic somite anomalies, unilateral renal agenesis, and conductive deafness are also seen. Mullerian aplasia and hyperandrogenism (158330) is caused by mutation in the WNT4 gene (603490). Familial cases of unilateral or bilateral renal agenesis in combination with mullerian anomalies have also been reported (see urogenital adysplasia, 191830).