De Sanctis-Cacchione syndrome is defined by the clinical triad of xeroderma pigmentosum (XP), intellectual deficit and neurological disturbances. It is an extremely rare syndrome but the exact prevalence is unknown. It is rarer than XP alone, which has a prevalence of 1/250,000. The disease is usually diagnosed in early infancy. De Sanctis-Cacchione syndrome is characterized by the cutaneous and ocular manifestations of classic XP (see this term). It can develop in any type of XP but is most often found in patients with XP complementation groups A or D. Dermatological changes include extreme skin sensitivity to ultraviolet (UV) light, abnormal skin pigmentation, and a high frequency of skin cancers (especially on sun-exposed skin). Ocular manifestations include photophobia, recurrent conjunctivitis, eyelid solar lentigines, ectropion, and symblepharon with ulceration and scarring. The most common associated neurological abnormalities are progressive mental deterioration, cerebellar ataxia, hyporeflexia or areflexia, choreoathetosis, spasticity. Motor and peripheral sensory nerves may be severely affected. Progressive sensorineural deafness, microcephaly, abnormal electroencephalographic findings and epilepsy may be present. Markedly retarded growth, short stature and gonadal hypoplasia occur in the majority of cases. Shortening of the Achilles tendons with eventual quadriparesis is occasionally reported. De Sanctis-Cacchione syndrome is inherited in an autosomal recessive manner and has been associated with mutations in the ERCC6 gene. Mutations in the same gene are implicated in Cockayne syndrome (see this term). Diagnosis is based on the clinical findings and may sometimes be confirmed by molecular testing. Differential diagnosis includes a wide range of syndromes that present with dermatological, ocular and neurological manifestations (acanthosis nigricans, Bloom syndrome, Cockayne syndrome, Hartnup syndrome, Rothmund-Thomson syndrome and Basal cell nevussyndrome; see these terms). Management requires a multidisciplinary approach. Precautionary measures and patient awareness of the need to avoid exposure to UV light are mandatory. Examination by a dermatologist should be recommended every 3 to 6 months. Any suspicious growths should be biopsied and treated (usually excised). Ophthalmological and neurological examinations should be proposed at least once a year. Prognosis is generally poor.
Last update: November 2008