Rothmund–Thomson syndrome

Rothmund-Thomson syndrome
File:Rothmund-Thomson syndrome.jpg Panel showing some clinical features of the RTS syndrome. A) Chronic phase of cheek poikiloderma (4-year-old girl). B) Poikiloderma with alopecia (21-year-old boy). C) Poikiloderma. D) Poikiloderma sparing the trunk (courtesy of Professor M. Paradisi, Rome). E) Photo distributed poikiloderma and valgism of the knees. F) Thumb aplasia (patient B). G) Bone defect seen by X-Rays: cystic-like destructive lesion of the humerus (distal epiphysis) without apparent solution of continuity of the cortical bone (patient E).
Classification and external resources
Specialty
ICD-10	Q82.8 (ILDS Q82.852)
ICD-9-CM	757.33
OMIM	268400
DiseasesDB	29891
eMedicine	derm/379
Patient UK	Rothmund–Thomson syndrome
MeSH	D011038
GeneReviews	Rothmund-Thomson Syndrome
Orphanet	2909

Rothmund–Thomson syndrome (RTS), also known as poikiloderma atrophicans with cataract or poikiloderma congenitale, is a rare autosomal recessive skin condition originally described by August von Rothmund (1830–1906) in 1868. Matthew Sydney Thomson (1894–1969) published further descriptions in 1936.

There have been several reported cases associated with osteosarcoma. A hereditary genetic basis, mutations in the DNA Helicase RECQL4 gene, causing problems during initiation of DNA replication has been implicated in the syndrome

Characteristics

• Sun-sensitive rash with prominent poikiloderma and telangiectasias
• Juvenile cataracts
• Saddle nose
• Congenital bone defects, including short stature and radial ray anomalies such as absent thumbs
• Hair growth problems (absent eyelashes, eyebrows and/or hair)
• Hypogonadism has not been well documented
• Hypodontia
• Calcium problems (not documented in journals)
• Ear problems (not documented in journals but identified by patients in support groups)
• Produces Osteosarcoma

The skin is normal at birth. Between 3 and 6 months of age, the affected carrier develops poikiloderma on the cheeks. This characteristic “rash” that all RTS carriers have can develop on the arms, legs and buttocks. “Poikiloderma consists of areas of increased and decreased pigmentation, prominent blood vessels, and thinning of the skin”

Cause and Genetics

Rothmund–Thomson syndrome has an autosomal recessive pattern of inheritance.

RTS is caused by a mutation of the RECQL4 gene, located at chromosome 8q24.3. The disorder is inherited in an autosomal recessive manner. This means the defective gene responsible for the disorder is located on an autosome (chromosome 8 is an autosome), and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder.

See also

• Poikiloderma vasculare atrophicans
• List of cutaneous conditions
• List of radiographic findings associated with cutaneous conditions

External links

• Rothmund-Thomson on PFOND - web-based service to promote the sharing of information about research, treatment and resources for rare genetic disorders.
• GeneReviews/NCBI/NIH/UW entry on Rothmund-Thomson Syndrome
• Poikiloderma of Rothmund-Thomson at NIH's Office of Rare Diseases
• RTSPlace.org