Congenital generalized hypertrichosis, in its most common form, is idiopathic. In the absence of underlying endocrine or metabolic disorders, congenital generalized hypertrichosis is rare in humans, affecting as few as one in a billion individuals and may be an isolated condition of the skin, or a component feature of other disorders or syndromes. Congenital generalized hypertrichosis terminalis is an extremely rare condition, a distinct subset of disorders with congenital hypertrichosis, presenting with excessive hair as the primary clinical feature. Congenital generalized hypertrichosis terminalis is characterized by universal excessive growth of pigmented terminal hair and often accompanied with gingival hyperplasia and/or a coarse face. Gingival hyperplasia may be delayed even until puberty. Its pathogenesis may be caused by one of the following mechanisms: conversion of vellus to terminal hairs and/or prolonged anagenetic stage, and/or increase in the number of hair follicles. Since the Middle Ages, less than 60 individuals with congenital hypertrichosis terminalis have been described, and, according to the most recent estimates, less than 40 cases were documented adequately and definitively in the literature. Recent articles identified congenital generalized hypertrichosis terminalis as a genomic disorder.
This report is a follow up of a six-year-old boy born from the first normal pregnancy of non-consanguineous parents, starting from delivery. Our investigation revealed a history of: excessive hair growth and a coarse face from birth; increased body weight with high blood pressure and gingival hyperplasia at the age of four months. The parents denied any medication or chemical intake during pregnancy, as well as a history of hypertrichosis in their families. The child had a congenital hydronephrosis of the right kidney. Ultrasound and magnetic resonance imaging revealed severe congenital hydronephrosis of the right kidney and suspicion of hypertrophy of the left adrenal gland suggestive of an adenoma. The follow up showed normal values of hormones which excluded adrenal tumor. At the age of 8 months the patient underwent right-sided nephrectomy after several urinary infections. The child was admitted again to our Clinic at the age of four years, with generalized hypertrichosis, gingival hyperplasia and a coarse face without any other pathological signs. He has had a normal intellectual development, but was extremely shy, unconfident and dependent on his mother. The relevant laboratory investigations showed normal full blood count, biochemical, hormonal test results and normal function of the single kidney. Molecular chromosome analysis revealed heterozygous deletion on chromosome 17q12 region. Prolonged follow-up with routine checkups every 6–12 months was advised, including regular outpatient appointments particularly with an endocrinologist, because of the risk of diabetes mellitus, and with a nephrologist, for control of renal function.
Laser hair removal was suggested and the patient underwent one procedure with long pulsed neodynium:yttrium-albumin-garnet laser with a wavelength of 1064 nm. The procedure was effective and well-tolerated and the treatment course is currently ongoing.
Although it is now believed that most people with congenital generalized hypertrichosis have an unknown genetic defect, up to date, a clear specific molecular abnormality has not been proved. It has been suggested that the distal portion of human chromosome 17q may contain dosage-sensitive genes that contribute to excessive hair growth.
We present a sporadic case of an extremely rare congenital generalized hypertrichosis terminalis in a six-year-old boy born to non-consanguineous parents, with gingival hyperplasia, a coarse face and congenital hydronephrosis, with heterozygous deletion on chromosomal region 17q12 consistent with his renal phenotype.
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