Genetic analysis of the confirmed pseudoxanthoma elasticum diagnosis and their relatives

Genetic Aıtâlvâjrof the Patients with Confirmed Pseudoxanthoma Elasticum Diagnosis and Their Relatives (SUMMARY) PXE is an otosomal dominant inherited disorder of connective tissue characterized by progressive calsification of elastic fibers in skin, retina, and cardiovascular system. Altough the averege age of onset in PXE is 13 years, most cases are not diagnosed until adulthood. PXE patients are known to be at risk for earry coronary artery disease and can experience angina and sudden death. For this reason early diagnosis ( before clinical manifestations) is most important in families at risk. The aim of this study is early diagnosis of PXE families, which individuals of family has probability of disorder and to advise protective measures to these individuals. In our study we determined pedigree of 17 person who has proband. Four patient (2 female and 2 male) who were diagnosed clinicary and histopatologycary PXE, used at our control grup. Remaining 13 family members is considered as risky grup and studied with compararative sitogenetk methods by using FISH and giemsa banding to see if they are genotypically sick. At this region numerical or structural anomalies are not found by Giemsa banding. In this study using FISH method on the region that detect ABCC6 gene, known as PXE gene, applying region specific MYH11 16pl3.1 prob, the daughter of the patient number 116, who does not show any clinical symptoms at the age 9, designated as numbered IQ7 demostrated a deletion on the PXE gene by FISH. All the family members of the informative family who had clinical PXE diagnosis has the same diagnosis. However other family members did not show this deletion which is proven by signal loss detection. Because of the variety and size of deletion it is not possible to use FISH method for screening suspected families. For the confirmation of the PXE, it must be used sense and antisense DNA sequence of the cases, considered to have deletion. So confirmation of suspected family members, PXE must be determine by using adevanced moleculer genetic means such as sequence analysis by capillary electrophoresis It is concludeted that FISH is useful, quick and a cheap method for pre-screening of family members who have PXE patients. Because sequence analysis is expensive there for it is not suitable for family pre-screening and that is why FISH method is suitable for screening high risk families who have not show clinically PXE symtomsyet. 54