Hereditary mucoepithelial dysplasia (HMD)
is a condition that affects the skin, hair, mucosa (areas of the body that are lined with mucus), gums (gingiva), eyes, nose and lungs. Symptoms typically begin in infancy and may include development of cataracts (clouding of the eye lens); blindness; hair loss (alopecia); abnormal changes to the perineum (the area between the anus and external genitalia); and small, skin-colored bumps (keratosis pilaris). Terminal lung disease has also been reported. The cause of HMD is thought to be an abnormality in desmosomes and gap junctions, which are structures involved in cell-to-cell contact. HMD typically follows autosomal dominant inheritance, but has occurred sporadically (in an individual who has no family history of the condition). Treatment typically focuses on individual symptoms of the condition. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.