[Heredity of psoriasis].

INTRODUCTION

Epidemiological studies of twins show that there is a genetic predisposition to psoriasis. Researches conducted so far show that psoriasis is a multifactorial polygenetic disease with reduced gene penetration. They also show that heredity is more significant than the "trigger" factor whose influence is limited to the exchange of phenotypes. Researches in USA, Canada and Europe identified four most important loci (psoriasis susceptibility--1-4). At least one is in MHC (major histocompatibility complex) due to the connection between psoriasis and alleles of human leukocyte antigen (HLA).

OBJECTIVE

Our study included 117 patients and examined the indicators of genetic predisposition to psoriasis: frequency of psoriasis among relatives of psoriatic probands; frequency of psoriasis among relatives (I and II degree) of psoriatic patients; age of probands and other relatives at the onset of illness.

MATERIAL AND

METHODS

We have used a structured questionnaire for collection of data about existence of psoriasis in relatives of I and II degree of psoriatic probands and about the age of probands and relatives at the time of onset.

RESULTS AND DISCUSSION: Twenty six (21.85%) probands have at least one ill relative. The examined patients who have diseased relatives get ill much earlier than those who do not. Probands with two or more diseased relatives get ill much earlier than those who have just one diseased relative. Analysis of our sample shows a significant statistical difference regarding the onset of illness of diseased parents and their children. Children get ill earlier.

CONCLUSIONS

We have concluded that in our sample there is a hereditary component which is related to frequency and onset of psoriasis.