Abstract: Porphyria cutanea tarda has a complex etiology with genetic factors not completely elucidated. The miscegenation of the Brazilian population has important implications in the predisposition to diseases. There are no studies concerning the genetic ancestry of patients with porphyria cutanea tarda from a mixed population. Thirty patients living in Rio de Janeiro with sporadic porphyria cutanea tarda were studied for the genetic ancestry through informative markers - INDELS. There was a significant predominance of European ancestry across the sample of patients with porphyria cutanea tarda (70.2%), and a small contribution of African and Amerindian ancestry, 20.1% and 10.9%, respectively.

A Síndrome de Bloch-Sulzberger (Incontinência Pigmentar) é uma genodermatose rara, que afeta, principalmente, o sexo feminino, pois costuma ser letal em pacientes do sexo masculino intraútero. Caracteriza-se, principalmente, pelas manifestações dermatológicas, podendo também apresentar anomalias dentárias, oftalmológicas e neurológicas. As lesões cutâneas apresentam 4 fases distintas: vesiculosa, verrucosa, pigmentar e atrófica; que podem seguir uma sequência irregular, havendo até sobreposição das mesmas

Bloch-Sulzberger syndrome (incontinentia pigmenti) is a rare genodermatosis that affects predominantly females, since it is generally lethal to male fetuses in utero. It is characterized principally by skin lesions, but may also involve dental, ophthalmological and neurological abnormalities. The skin lesions are present in four different phases: vesicular, verrucous, hyperpigmented and atrophic/hypopigmented. Their sequence is irregular and overlapping of stages is common

A síndrome de Christ-Siemens-Touraine (displasia ectodérmica hipoidrótica) é uma síndrome rara, caracterizada pela tríade de sudorese reduzida ou ausente, hipotricose e dentição defeituosa. Bossas frontais proeminentes, nariz em sela, lábio inferior espesso e queixo pontudo fazem com que os pacientes tenham uma fácies característica e semelhante. A síndrome completa ocorre em homens, visto tratar-se de herança recessiva ligada ao X.

Christ-Siemens-Touraine syndrome (hypohidrotic ectodermal dysplasia) is a rare syndrome characterized by the triad of absent or reduced sweating, hypotrichosis, and defective dentition. The prominent forehead, saddle nose, thick lower lip and pointy chin produce a distinctive facies. The full syndrome only occurs in men as it is an X-linked recessive condition.