Poikiloderma, juvenile cataracts, skeletal disorders, and malignancy predisposition (skin and osseous). Trisomy 8 mosaicism is frequent. Maintaining hydration is a major concern.
Poikiloderma Atrophicans and Cataract; Poikiloderma Congenitale.
Very rare. Approximately 300 cases are described.
Two forms of Rothmund-Thomson Syndrome have been described. Type 1 presents with poikiloderma, ectodermal dysplasia, and juvenile cataracts and Type 2 is characterized by poikiloderma, skeletal deformities, and a predisposition to cancer. Type 2 is caused by mutations in a recQ helicase gene (RECQL4) at locus 8q24.3 in approximately two-thirds of these patients.
Clinical, evocated by the association of skin abnormalities (starting in infancy), skeletal disorders, juvenile cataract, and predisposition to malignancy and characteristic rash. Karyotype may show abnormalities of chromosome 8 in a minority of patients.
The skin changes begin within the first year of life in 89% of patients. These are defined as erythematous patches or red edematous plaques, sometimes accompanied by blistering. Characteristically, these begin on the cheek and spread to the forehead, ears, and neck. Usually by this time, erythema has also appeared on the dorsal aspects of the hands, extensor aspects of the arms and forearms, and the legs and buttocks. Poikiloderma is a feature of atrophy, areas of hyper- and hypopigmentation, and telangiectases. Skin, nails, and hair are primarily involved: erythematous or bullous skin lesions, poikiloderma (atrophic plaques with telangiectasia), telangiectasia, skin atrophy, sun sensitivity (35%), abnormal scar formation, atrophic nails (24%), sparse hair, alopecia. Premature graying of hair can frequently be observed and may be associated with short stature (54%), mental retardation, and facial deformation: frontal bossing, prognathism, small saddle nose, dental and ocular anomalies (juvenile zonular cataracts [52%], microphthalmia, microcornea, strabismus, glaucoma). Skeletal repercussions also concern limbs with osteoporosis, forearm reduction defects, absence of patella joint, contractures, thumb hypoplasia, small hands, and small and club feet. Other clinical features are occasional and can affect digestive area (annular pancreas, anterior positioning of the anus, duodenal stenosis) and genitourinary structures (hypogonadism, cryptorchidism nephritis, or nephropathy with vascular hypertension). Anemia, growth hormone deficiency, and immunoglobulin abnormality have also been reported. There is an increased risk of basal cell carcinoma, squamous cell carcinoma, and osteogenic sarcoma. Treatment includes constant use of sunscreen and avoidance of sun exposure. Regular ophthalmic screening and evaluation of any bone pain are mandatory. One case was described with Addison disease and one case was described with growth hormone deficiency.
Rothmund-Thomson Syndrome: These erythematous skin changes are caused by photosensitivity in this infant with Rothmund-Thomson Syndrome.