U6 snRNA Phosphodiesterase (USB1)

Defects in C16orf57 are the cause of poikiloderma with neutropenia (PN). PN is a genodermatosis characterized by poikiloderma, pachyonychia and chronic neutropenia. The disorder starts as a papular erythematous rash on the limbs during the first year of life. It gradually spreads centripetally and, as the papular rash resolves, hypo- and hyperpigmentation result, with development of telangiectasias.

The deduced 265-amino acid protein contains 5 helical domains and is highly conserved among vertebrates. C16ORF57 was significantly expressed in myeloid lineage cells. C16ORF57 gene contains 7 exons.In 3 affected sibs from a highly consanguineous Italian family with poikiloderma and neutropenia (PN),