Milia. A milium is a white papule, 1–2 mm in size, composed of laminated, keratinous material and situated as a solid cyst in a pilosebaceous follicle. Milia are fairly common on the brow, glabella, and nose in newborn infants and in such infants tend to disappear quickly and spontaneously. There may be few or many, and they may develop later in infancy, in childhood, and in adolescence. In older children and adolescents, they tend to macules may be sparse or numerous and resolve without residua over a period of several weeks to several months.
Nail-patella syndrome. This entity, also known as hereditary osteo-onychodysplasia, is a genetic disease linked to a mutation in the gene encoding transcription factor LMX1B, mapped on the long arm of chromosome 9 (9q34). The manifestations include fingernail dysplasia, absent or hypoplastic patellae, the presence of posterior conical iliac horns, and abnormalities of the radial heads. Patients are also at risk for kidney disease and glaucoma.