Rothmund-Thomson Syndrome Type 2

Rothmund-Thomson syndrome type 2 is a subform of Rothmund-Thomson syndrome (RTS; see this term) presenting with a characteristic facial rash (poikiloderma) and frequently associated with short stature, sparse scalp hair, sparse or absent eyelashes and/or eyebrows, congenital bone defects and an increased risk of osteosarcoma in childhood and squamous cell carcinoma later in life.

Epidemiology

Around 300 cases of RTS have been reported in the literature so far, with RTS2 accounting for around two-thirds of the cases.

Clinical description

The skeletal abnormalities may be overt (such as frontal bossing, saddle nose and congenital radial ray defects), and/or subtle anomalies visible only by radiographic analysis.

Etiology

RTS is transmitted as an autosomal recessive trait and RTS2 is caused by homozygous or compound heterozygous mutations in the RECQL4 gene (8q24.3), whereas the etiology of RTS1 (see this term) remains unknown.