Abstract

RIDDLE syndrome is a rare genetic syndrome. The name is an acronym for Radiosensitivity, ImmunoDeficiency Dysmorphic features and LEarning difficulties.

Epidemiology

This condition is rare. Only four cases have been described up to 2017.

Genetics

This condition is due to mutations in the RNF168 gene. It is inherited in an autosomal recessive fashion.

The gene encodes a ubiquitin ligase and is located on the long arm of chromosome 3 (3q29) on the Crick (minus strand).

Clinical

The features of this condition include

- Facial dysmorphism

- Short stature

- Mild motor control and learning difficulties

- Mild ataxia

- Microcephaly

- Normal intelligence

- Conjunctival telangiectasia

- Recurrent sinus infections

- Decreased serum IgA

- Late onset of pulmonary fibrosis

- Increased alpha-fetoprotein

- Increased radiosensitivity