PCR-Based Detection of Parental Origin of Extra Chromosome 21 in Down Syndrome
نویسندگان
چکیده
منابع مشابه
Phenotypic heterogeneity and parental origin of extra chromosome 21 in Down syndrome.
We compared the frequency of phenotypic features of 40 children with Down syndrome between individuals with a maternally or paternally derived extra chromosome 21, using quantitative FISH for comparing heteromorphisms of the nucleolar organizing region. Parental origin was determined in 90% of families. Hypotonia and craniofacial abnormalities were present in 90% or more individuals, irrespecti...
متن کاملIdentical monochorionic twins with down syndrome and paternal origin of the extra chromosome 21.
UNLABELLED Trisomy 21, the cause of Down syndrome (DS), is the most frequent trisomy in humans. The risk for DS increases with maternal age: mothers under 25 years of age are known to have an average risk of a DS pregnancy of 1: 1600, rising to 1: 350 at age 35 and to 1: 40 at 43, respectively. Twins with DS are rare. We report on monozygotic (MZ), monochorionic twin sisters with DS, whose pare...
متن کاملDown syndrome: genetic recombination and the origin of the extra chromosome 21.
Despite the clinical importance of trisomy 21, we have been ignorant of the causes of meiotic nondisjunction of chromosome 21. Recently, however, genetic mapping studies of trisomy 21 families have led to the identification of the first molecular correlate of human nondisjunction; i.e. altered levels and positioning of meiotic recombinational events. Specifically, increases in 0 exchange events...
متن کاملبررسی ژنتیکی ریزماهواره‌های کروموزوم 21 در جمعیت آذربایجان‌شرقی و کاربرد آن‌ها در تشخیص مبتلایان به سندروم داون
Background & Objective: Down syndrome is one of the most common chromosome aneuploidies causing mental retardation which occurs in approximately 1/230 pregnancies. It is usually caused by the presence of an extra chromosome 21. The aim of this study was to evaluate the simple PCR based DNA diagnostic method and also to determine the parental origin of the extra chromosome 21 in trisomal Down sy...
متن کاملParental origin, nondisjunction, and recombination of the extra chromosome 21 in Down syndrome: a study in a sample of the Colombian population.
INTRODUCTION Free trisomy 21 is responsible for 95% of Down syndrome cases. Advanced maternal age and susceptible recombination patterns are recognized risk factors associated to Down syndrome. Maternal origin of trisomy occurs in approximately 90% of cases; paternal and mitotic origin share the remaining 10%. However, the recombination events that serve as a risk factors for trisomy 21 have no...
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ژورنال
عنوان ژورنال: INTERNATIONAL JOURNAL OF HUMAN GENETICS
سال: 2005
ISSN: 0972-3757,2456-6330
DOI: 10.31901/24566330.2005/05.03.04