Biomaterial Database

[Cytogenetic findings in patients with Down's syndrome]. 1990

F Cortés, and M Alliende, and B Curotto

Unidad de Genética, INTA, Universidad de Chile.

In order to describe the frequency of non classical forms of 21 trisomy in patients with Down's syndrome at the cytogenetic's laboratory of our institution (Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile) 201 chromosomal studies from peripheral blood lymphocytes of patients referred with a clinical diagnosis of Down's syndrome were analyzed. Among them 22 (11%) cases showed no chromosomal abnormalities, 161 (80%) had classic 21 trisomy, 7 (3.5%), showed 21 trisomy by translocation, 5 (2.5%) had 21 trisomy mosaicism, 6 (3%) showed 21 trisomy plus an autosomic balanced translocation. Male to female rate was 1.18:1 and diagnosis was done at the neonatal period in 26.8% of cases. Early recognition of the different kinds of chromosomal abnormalities in Down's syndrome is important if appropriate genetic council is the goal.

UI	MeSH Term	Description	Entries
D007223	Infant	A child between 1 and 23 months of age.	Infants
D007231	Infant, Newborn	An infant during the first 28 days after birth.	Neonate,Newborns,Infants, Newborn,Neonates,Newborn,Newborn Infant,Newborn Infants
D008297	Male		Males
D009030	Mosaicism	The occurrence in an individual of two or more cell populations of different chromosomal constitutions, derived from a single ZYGOTE, as opposed to CHIMERISM in which the different cell populations are derived from more than one zygote.
D002675	Child, Preschool	A child between the ages of 2 and 5.	Children, Preschool,Preschool Child,Preschool Children
D002891	Chromosomes, Human, Pair 21	A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.	Chromosome 21
D004314	Down Syndrome	A chromosome disorder associated either with an extra CHROMOSOME 21 or an effective TRISOMY for chromosome 21. Clinical manifestations include HYPOTONIA, short stature, BRACHYCEPHALY, upslanting palpebral fissures, epicanthus, Brushfield spots on the iris, protruding tongue, small ears, short, broad hands, fifth finger clinodactyly, single transverse palmar crease, and moderate to severe INTELLECTUAL DISABILITY. Cardiac and gastrointestinal malformations, a marked increase in the incidence of LEUKEMIA, and the early onset of ALZHEIMER DISEASE are also associated with this condition. Pathologic features include the development of NEUROFIBRILLARY TANGLES in neurons and the deposition of AMYLOID BETA-PROTEIN, similar to the pathology of ALZHEIMER DISEASE. (Menkes, Textbook of Child Neurology, 5th ed, p213)	Mongolism,Trisomy 21,47,XX,+21,47,XY,+21,Down Syndrome, Partial Trisomy 21,Down's Syndrome,Partial Trisomy 21 Down Syndrome,Trisomy 21, Meiotic Nondisjunction,Trisomy 21, Mitotic Nondisjunction,Trisomy G,Downs Syndrome,Syndrome, Down,Syndrome, Down's
D005260	Female		Females
D005817	Genetic Counseling	An educational process that provides information and advice to individuals or families about a genetic condition that may affect them. The purpose is to help individuals make informed decisions about marriage, reproduction, and other health management issues based on information about the genetic disease, the available diagnostic tests, and management programs. Psychosocial support is usually offered.	Counseling, Genetic,Genetic Counseling, Prenatal,Prenatal Genetic Counseling
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man