D own’s syndrome is caused by trisomy of chromosome 21. This invariably results in cognitive impairment, hypotonia, and characteristic phenotypic features such as flat facies, upslanting palpebral fissures, and inner epicanthal folds, and variations in digits and the ridge formation on hands and feet. Furthermore, trisomy 21 is a risk factor for congenital heart disease, Hirschsprung’s disease,...

Partial monosomy 10q25.2----qter, detected in a newborn baby with multiple congenital abnormalities, was found to be derived from a balanced maternal translocation t(6;10)(q27;q25.2). The pedigree of six generations of the family is presented. In an extensive cytogenetic study of this family, the chromosome complements of 57 subjects, potentially capable of carrying some form of this translocat...

Partial trisomy 9 is a common autosomal trisomy, which is characterized by non-specific psychomotor delay, mental retardation and moderately abnormal characteristic facial features. Generally, partial trisomy 9 leads to variable phenotypes depending on the size and position of the duplicated region. However, a precise genotype/phenotype map has not been determined. The present study reports the...

The phenotype of partial trisomy 9p includes global developmental delay, microcephaly, bulbous nose, downturned oral commissures, malformed ears, hypotonia, and severe cognitive and language disorders. We present a case report and a comparative review of clinical findings on this condition, focusing on speech-language development, cognitive abilities and swallowing evaluation. We suggest that o...

D own’s syndrome is caused by trisomy of chromosome 21. This invariably results in cognitive impairment, hypotonia, and characteristic phenotypic features such as flat facies, upslanting palpebral fissures, and inner epicanthal folds, and variations in digits and the ridge formation on hands and feet. Furthermore, trisomy 21 is a risk factor for congenital heart disease, Hirschsprung’s disease,...

A case of partial trisomy of the long arm of chromosome 3 (3q21 leads to qter) is described. The clinical findings are compared with those in 5 previously reported cases. There is hirsutism and characteristic facial dysmorphism, the common features of which are a square-shaped face, prominent nasal bridge, everted nostrils, hypertelorism, and palate abnormalities; occurring less often are abnor...

We describe a trisomy 21 with a small supernumerary marker chromosome (sSMC) derived from chromosomes 13/21 and 18 in which the karyotype was 48,XY,+der(13 or 21)t(13 or 21;18)(13 or 21pter→13q11 or 21q11.1::18p 11.21→18pter),+21. Of the 35 case reports in the literature for a karyotype 48,XN,+21,+mar, in only 12 was the origin of the sSMC determined by fluorescence in situ hybridization (FISH)...