Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1987 Aug;76(4):344-7.
doi: 10.1007/BF00272442.

Frequency of the fragile X syndrome in institutionalized mentally retarded females in Japan

T Arinami, I Kondo, S Nakajima, H Hamaguchi

Frequency of the fragile X syndrome in institutionalized mentally retarded females in Japan

T Arinami et al. Hum Genet. 1987 Aug.

Abstract

The fragile X [fra(X)] syndrome was screened on 190 Japanese institutionalized females with moderate to severe mental retardation. Two inmates with severe mental retardation (IQ 20) had the fra(X) chromosome in 26% and 15% of the cells examined, indicating that the prevalence of the fra(X) syndrome was about 1% in all female inmates and was about 3.27% in severely mentally retarded females without known causes. However, no female with fra(X) syndrome was found in 35 moderately retarded females. Both had brothers with the fra(X) syndrome and the prevalence was 10% in females with a family history of mental retardation. In addition, the replication study of the fra(X) chromosome in the patients supported the proposal that an excess of the early replicated fra(X) chromosome is related to the mental capacity in heterozygous females. Therefore, the fra(X) syndrome should not be ignored even in severely mentally retarded females with a family history, though the heterozygotes are commonly normal to subnormal in their mental development. In addition, the replication study of the fra(X) chromosome may help to estimate mental development in the carrier children.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

References

    1. Hum Genet. 1981;59(1):23-5 - PubMed
    1. Am J Hum Genet. 1982 May;34(3):452-8 - PubMed
    1. J Med Genet. 1984 Oct;21(5):373 - PubMed
    1. Hum Genet. 1984;66(4):344-6 - PubMed
    1. J Med Genet. 1986 Oct;23(5):407-10 - PubMed

LinkOut - more resources