Hajdu Cheney Syndrome: A Comprehensive Medical Review Introduction Hajdu Cheney syndrome (HCS) is an extremely rare autosomal dominant connective tissue disorder characterized by progressive bone resorption, distinctive craniofacial features, and multisystem involvement. First described by Nicholas Hajdu in 1948 and further characterized by William Douglas Cheney in 1965, this syndrome represents one of the rarest …
Hairy Throat Syndrome: A Comprehensive Medical Review Introduction Hairy throat syndrome, medically known as anterior cervical hypertrichosis (ACH), is an extremely rare form of localized congenital hypertrichosis characterized by the presence of a tuft of terminal hair on the anterior neck, typically located just above the laryngeal prominence. First described by Trattner et al. in …
Hairy Elbows Syndrome: A Comprehensive Medical Review Introduction Hairy elbows syndrome, also known as hypertrichosis cubiti or congenital circumscribed hypertrichosis of the elbows, is an extremely rare genetic condition characterized by excessive growth of long, fine hairs on the extensor surfaces of the upper extremities, particularly concentrated around the elbow region. First described by Dr. …
Hair Nail Ectodermal Dysplasia – Introduction Hair-nail ectodermal dysplasia, also known as pure hair and nail ectodermal dysplasia or ectodermal dysplasia type 4 (ECTD4), represents a rare subset of the ectodermal dysplasia syndromes characterized by isolated abnormalities affecting only hair and nail development without other systemic manifestations. This condition was first molecularly characterized through the …
Haim Munk Syndrome: A Comprehensive Medical Review Introduction Haim-Munk syndrome (HMS), also known as keratosis palmoplantaris with periodontopathia and onychogryphosis or Cochin Jewish disorder, is an extremely rare autosomal recessive genodermatosis first described by dermatologist Salim Haim and radiologist J. Munk in 1965. The syndrome was initially identified in four siblings from a consanguineous Jewish …
Hailey Hailey Disease: A Comprehensive Medical Review Introduction Hailey-Hailey disease (HHD), also known as familial benign chronic pemphigus or benign familial pemphigus, is a rare, chronic, and relapsing autosomal dominant genodermatosis first described by brothers Hugh Edward and William Howard Hailey in 1939. Despite its designation as “benign,” the condition causes significant morbidity and substantially …
Hagberg-Santavuori Disease: A Comprehensive Medical Review Introduction Hagberg-Santavuori disease, also known as infantile neuronal ceroid lipofuscinosis (INCL), classic infantile CLN1 disease, or Santavuori disease, is a rare, progressive, and fatal neurodegenerative disorder that represents the most severe and earliest-onset form of neuronal ceroid lipofuscinosis (NCL). First described by Bengt Hagberg and Pirkko Santavuori in the …