Down syndrome phenotypes: The consequences of chromosomal imbalance

Journal Article · Tue May 24 00:00:00 EDT 1994 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.91.11.4997· OSTI ID:6792626

Korenberg, J R; Chen, X N; Schipper, R; Sun, Z; Gonsky, R; Gerwehr, S; Graham, Jr, J M ^[1]; Carpenter, N; Say, B ^[2]; Daumer, C ^[3]

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1. Univ. of California, Los Angeles, CA (United States)
2. H.A. Chapman Institute of Medical Genetics, Tulsa, OK (United States)
3. Univ. of Munich (Germany); and others

Down syndrome (DS) is a major cause of mental retardation and congenital heart disease. Besides a characteristic set of facial and physical features, DS is associated with congenital anomalies of the gastrointestinal tract, an increased risk of leukemia, immune system defects, and an Alzheimer-like dementia. Moreover, DS is a model for the study of human aneuploidy. Although usually caused by the presence of an extra chromosome 21, subsets of the phenotypic features of DS may be caused by the duplication of small regions of the chromosome. The physical map of chromosome 21 allows the molecular definition of the regions duplicated in these rare cases of partial trisomy. As a first step in identifying the genes responsible for individual DS features and their pathophysiology, a panel of cell lines derived from 16 such individuals has been established and the molecular break points have been determined using fluorescence in situ hybridization and Southern blot dosage analysis of 32 markers unique to human chromosome 21. Combining this information with detailed clinical evaluations of these patients, the authors have now constructed a [open quotes]phenotypic map[close quotes] that includes 25 features and assigns regions of 2-20 megabases as likely to contain the genes responsible. This study provides evidence for a significant contribution of genes outside the D21S55 region to the DS phenotypes, including the facies, microcephaly, short stature, hypotonia, abnormal dermatoglyphics, and mental retardation. This strongly suggests DS is a contiguous gene syndrome and augurs against a single DS chromosomal region responsible for most of the DS phenotypic features.

• OSTI ID: 6792626
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 91:11; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
DOWNS SYNDROME
PATHOGENESIS
HUMAN CHROMOSOME 21
ANEUPLOIDY
GENETIC MAPPING
DNA HYBRIDIZATION
BIOTECHNOLOGY
CHROMOSOMES
CONGENITAL DISEASES
CONGENITAL MALFORMATIONS
DISEASES
GENETIC ENGINEERING
HEREDITARY DISEASES
HUMAN CHROMOSOMES
HYBRIDIZATION
MALFORMATIONS
MAPPING
NUCLEIC ACID HYBRIDIZATION
PATHOLOGICAL CHANGES
PLOIDY
550400* - Genetics
550900 - Pathology