Photosensitive Trichothiodystrophy with Complex Cerebral Abnormalities

Aims: Trichothiodystrophy (TTD) is a rare ectodermal disorder with congenital hair dysplasia and autosomal recessive inheritance. Tiger tail banding under polarized light and low sulfur content of hair plus trichoschisis are pathognomic for this disorder. Most mutations are found in the ERCC2/XPD and ERCC/XPB gene in the long arm of chromosome 19. In the case of photosensitivity, the disease is typically associated with additional DNA repair defects which can be classified by distinct mutations.

Methods: The 5th male baby of non consanguineous parents from Chechenia showed severe congenital dystrophy and microcephaly, ichthyosiform erythroderma (collodion baby), cataract, typical sparse and brittle hair as well as onychodystrophy which led to clinical diagnosis of TTD. The diagnosis was confirmed by the tiger tail banding and reduced sulfur content of hair. At the age of 5 weeks, the child died after recurrent apnea and aspiration.

A male sibling also died in 2004at the age of 3 month presenting with an identical phenotype.

Results: Autopsy affirmed cerebral abnormalities with pachygyria, aplasia of corpus callosum and hypoplasia of cerebellum and vermis. Histologically a cortical migration disorder was conspicuous. The karyotype was normal (46, XY). The genetic results concerning our case are not yet completed.

Conclusion: TTD is a rare ectodermal disorder. A new classification scheme has been developed in 2009 focusing on two distinct different entities concerning in vitro photosensitivity and additional genetic mutations in DNA repair mechanisms.

Concerning our child the cerebral abnormalities are conspicuous.

trichothiodystrophy - tiger tail banding - XPD Gene