Cytogenetic studies in a selected group of mentally retarded children

Abstract

Chromosomal abnormalities are an important cause of mental retardation. We studied the frequency of karyotype abnormalities in 74 mentally retarded patients selected from 306 patients referred to our clinic. Giemsa-banding was done on all cases. Additional studies in abnormal cases included autoradiography and X and Y chromatin. Karyotype analyses and blood group (Xg and Duffy) studies were carried out in family members in some cases. Fourteen of these children had chromosomal abnormalities, seven sex chromosomal, and seven had autosomal abnormalities. Three patients had 45,X and one had a 45,X/46,Xr(X) karyotype. Other sex chromosomal abnormalities were 46,XX/48,XXXX; 48,XXXY/49,XXXXY; and 48,XXYY. Autosomal abnormalities were 46,XX,1q-; 46,XY,2q-; 46,XY,5p-; 46,XY,dup(5p); 45,XX,t(13,14); and 46,XY,17p-. This is the first report from India of cytogenetic abnormalities in idiopathic mental retardation. The chromosomal studies in these patients help not only in accurate diagnosis, proper prognosis, and genetic counseling but also in gene localization and in the study of the origin of X-chromosome abnormalities.

A patient defines the interstitial 1q deletion syndrome characterized by antithrombin III deficiency

“…Three of these reports described only a few phenotypic features [Moghe et al, 1981;Higgins et al, 1982;Martin and Simpson, 1982] and, as well as in the report of Franco et al [1991], patient's photographs were lacking.…”

Chromosomal and biochemical screening on mentally retarded school children in Taiwan

“…Various surveys have been carried out in the past two decades in different parts of the world to karyotype patients with mental retardation (Sutherland and Wiener, 1971;Cassiman et aL, 1975;Coco and Penchaszadeh, 1976;Speed et aL, 1976;Sutherland et al, 1976;Jacobs et aL, 1978;Moghe et aL, 1981;Wuu et al, 1984). Some researchers have examined the chromosomes of all mental retardates in an institution (Jacobs et aL, 1978) or in a regional population (Speed et aL, 1976), while others have selected the patients before karyotyping (Coco and Penchaszadeh, 1976;Moghe et aL, 1981). These studies unequivocally demonstrate that mentally retarded patients with associated congenital abnormalities have a higher frequency of chromosomal abnormalities than those without.…”

A de novo 1q22q23.1 Interstitial Microdeletion in a Girl with Intellectual Disability and Multiple Congenital Anomalies Including Congenital Heart Defect

“…Interstitial deletions of the medial long arm of chromosome 1 are rare. More than 10 patients with interstitial deletions that include all or part of 1q22q23 have been reported to date [de Pablo et al, 1980;Moghe et al, 1981;Taysi et al, 1982;Beemer et al, 1985;Leichtman et al, 1993;Melis et al, 1998;Schinzel, 2001;Quinonez et al, 2012]. The most common anomalies observed in patients include DD/ID, postnatal growth deficiency, congenital heart defects, and dysmorphic features.…”