Heterozygous female carriers of the marker-X-chromosome: IQ estimation and replication status of fra(X)(q).
The IQ levels of 18 female carriers with the marker X chromosome were evaluated, and cytogenetic studies after BrdU incorporation were performed. A highly significant correlation between mental capacity and replication pattern of the X chromosomes could be demonstrated. Heterozygous females with normal intelligence showed a clear tendency to carry the fragile site at the late replicating X chromosome, while other female carriers with lower intelligence or mental impairment expressed their fragile site mainly with the early replicating X chromosome. This observation could be interpreted as an expression of Lyonisation .
18 references, click to expand
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X-linked mental retardation with fragile X. A pedigree showing transmission by apparently unaffected males and partial expression in female carriers.Hum Genet. 1981;59(1):23-5 PMID: 10819017
-
The fragile X(q27) form of X-linked mental retardation: FUdR as an inducing agent for fra(X)(q27) expression in lymphocytes, fibroblasts, and amniocytes.Am J Med Genet. 1982 Oct;13(2):139-48 PMID: 6215863
-
Additional evidence for fragile X activity in heterozygous carriers.Am J Hum Genet. 1983 Sep;35(5):861-8 PMID: 6614002
-
Screening for fra(X)(q) in a population of mentally retarded males.Hum Genet. 1983;63(2):153-7 PMID: 6682403
-
Carrier detection and X-inactivation studies in the fragile X syndrome. Cytogenetic studies in 63 obligate and potential carriers of the fragile X.Hum Genet. 1983;64(3):240-5 PMID: 6885068
-
Heterozygous expression of X-linked mental retardation and X-chromosome marker fra(X)(q27).N Engl J Med. 1980 Sep 18;303(12):662-4 PMID: 6931286
-
Fragile (X)(q27) sites in a pedigree with female carriers showing mild to severe mental retardation.J Med Genet. 1982 Feb;19(1):44-8 PMID: 7069746
-
Fragile site Xq27 and mental retardation. Clinical and cytogenetic manifestation in heterozygotes and hemizygotes of five kindreds.Hum Genet. 1982;60(4):322-7 PMID: 6955257
-
Replication status of the fragile X chromosome, fra(X)(q27), in three heterozygous females.Hum Genet. 1982;62(3):282-4 PMID: 7169220
-
Fragile X-linked mental retardation. A survey of 65 patients with mental retardation of unknown origin.Am J Dis Child. 1982 May;136(5):392-8 PMID: 7081157
-
Heritable fragile sites on human chromosomes I. Factors affecting expression in lymphocyte culture.Am J Hum Genet. 1979 Mar;31(2):125-35 PMID: 36752
-
[Short forms of a short psychopathological intelligence test (author's transl)].MMW Munch Med Wochenschr. 1976 Feb 27;118(9):259-62 PMID: 817191
-
Activity of the fragile X in heterozygous carriers.Am J Hum Genet. 1982 Mar;34(2):286-93 PMID: 6176123
-
X-linked mental retardation: a study of 7 families.Am J Med Genet. 1980;7(4):471-89 PMID: 7211957
-
Fragile (X) X-linked mental retardation I: relationship between age and intelligence and the frequency of expression of fragil (X)(q28).Am J Med Genet. 1983 Apr;14(4):699-712 PMID: 6846402
-
X-linked mental retardation with macro-orchidism and marker X chromosomes.Hum Genet. 1979 Sep;50(3):247-51 PMID: 489008
-
X-linked mental retardation with macro-orchidism and marker-X chromosomes.Am J Med Genet. 1980;7(4):433-41 PMID: 6938132
-
Replication pattern in XXY cells with fra(X).Hum Genet. 1982;60(3):278-80 PMID: 7201972
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