PORFIRIA CUTÁNEA TARDÍA EN ARGENTINA

CERBINO, GABRIELA; BUZALEH ANA MARIA; MENDEZ MANUEL; MELITO, VIVIANA; PARERA VICTORIA; VARELA, LAURA; COLOMBO, FEDERICO; ROSSETTI, MARIA VICTORIA

Sofia

Congreso; PORPHYRINS AND PORPHYRIAS 2022 (ICPP 2022; 2022

European Poprphyria Network

BackgroundPorphyria Cutanea Tarda (PCT) is the most common porphyria in Argentina (prevalence 1:20,000). There are two main types: PCT-A (acquired, sporadic or type I) and PCT-H (hereditary or type II). Type I is the most common form of PCT (70-80%) and the deficiency in Uroporphyrinogen decarboxylase (URO-D) is restricted to the liver. In PCT type II blood URO-D activity is reduced by 50%. The manifestation of PCT is associated with triggering factors: alcohol consumption, hormones and iron overload. The association between PCT and other pathologies is remarkable: hereditary haemochromatosis (HH), HCV and HIV. The aim of this study was to analyze the patients diagnosed in CIPYP with PCT to date to evaluate the incidence of the different types of PCT in our population. All patients signed the Informed consent.ResultsAmong 2230 PCT cases analyzed, 92% were PCT-A; 79% male and 21% female, in a 3.7:1 ratio. In the PCT-H cohort, 179 were symptomatic and 43 were latent in a 1.3:1 male:female ratio in both cases. 16.4% of the PCTs were HIV+ and 34% were HCV+. Only 4.3% were HH, 31.6% carried p.H63D (26.5% heterozygous, 5.1% homozygous). 6.8% carried the p.C282Y mutation (5.1% heterozygous, 1.7% homozygous) and 2.6% were heterozygous for both mutations.In the 84 unrelated PCT-H families, 45 different pathogenic variants were found, of which 16 were reported for the first time in CIPYP. In 23 families, the c.10-12insA variant (27%) was detected, being the most frequent in the country. The second was p.M165R (8%) and in third place p.N304K (7%), which together represent 38% of the allelic variants characterized. We also diagnosed 25 cases of childhood PCT, carrying c.10-12insA (8 cases) and p.M165R (2 cases).ConclusionAlthough PCT-H is inherited in an autosomal dominant manner with low penetrance, there are multiple triggering factors. Genetic diagnosis is of utmost importance as it allows counselling about contact with such agents to avoid the clinical expression in latent cases