A case of melanoma in xeroderma pigmentosum.

Xeroderma pigmentosum (XP) was first described in 1874 by Hebra and Kaposi. [1] It is a rare autosomal recessive disorder characterized by photosensitivity, pigmentary changes, premature skin aging, and malignant tumor development due to cellular hypersensitivity to ultraviolet radiation resulting from a defect in DNA repair. The basic defect in XP is in nucleotide excision repair (NER), leading to deficient repair of damaged DNA. A 12-year-old boy presented with a large growth over the right side of the forehead. The lesion was first noticed before two years as a 2 x 2 cm 2 mass. It was slowly growing and attained the present size of 10 x 8 x 7 cm 3 . The surface showed ulceration with areas of hemorrhage and blackish pigmentation. Also, the patient had hyperpigmented macules over the skin since early childhood. The macules appeared initially over the face and later developed over the other areas of the body. The macules were more over the sun exposed areas. He also had photophobia and both eyes showed corneal opacities. Histopathological examination of the excised growth showed features consistent with melanoma. This case is being presented because of its rare association with xeroderma pigmentosum patients in India.

Homocystinuria due to cystathionine beta synthase deficiency.

A two year-old male child presented with cutis marmorata congenita universalis, brittle hair, mild mental retardation, and finger spasms. Biochemical findings include increased levels of homocysteine in the blood-106.62 micromol/L (normal levels: 5.90-16 micromol/L). Biochemical tests such as the silver nitroprusside and nitroprusside tests were positive suggesting homocystinuria. The patient was treated with oral pyridoxine therapy for three months. The child responded well to this therapy and the muscle spasms as well as skin manifestations such as cutis marmorata subsided. The treatment is being continued; the case is reported here because of its rarity. Homocysteinuria arising due to cystathionine beta-synthase (CBS) deficiency is an autosomal recessive disorder of methionine metabolism that produces increased levels of urinary homocysteine and methionine It manifests itself in vascular, central nervous system, cutaneous, and connective tissue disturbances and phenotypically resembles Marfan's syndrome. Skin manifestations include malar flush, thin hair, and cutis reticulata / marmorata.