Prenatal diagnosis of the fragile-X in male monozygotic twins: Discordant expression of the fragile site in amniocytes

1985 ◽  
Vol 5 (3) ◽  
pp. 229-231 ◽  
Author(s):  
M. Rocchi ◽  
V. Pecile ◽  
N. Archidiacono ◽  
G. Monni ◽  
Y. Dumez ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Fragile Site ◽  
Fragile X ◽  
Monozygotic Twins

A Case of Mosaicism with Fragile-X and XXY Components

1987 ◽  
Vol 150 (5) ◽  
pp. 700-702 ◽  
Author(s):  
Saumitra Deb ◽  
Valerie A. Cowie ◽  
Carol Timberlake
Keyword(s):  
Cell Lines ◽  
Fragile Site ◽  
Fragile X ◽  
Chromosomal Mosaicism ◽  
Mentally Handicapped ◽  
Phenotypic Features

The case of a 63-year-old severely mentally handicapped man is reported with chromosomal mosaicism. His karyotype was established as mosaic 46XY/47XXY with the fragile site present in a proportion of cells of both cell-lines. He showed phenotypic features which could be related both to the fragile-X and Klinefelter's syndromes.

Rapid Fragile X Carrier Screening and Prenatal Diagnosis Using a Nonradioactive PCR Test

1994 ◽  
Vol 49 (4) ◽  
pp. 236-237
Author(s):  
W. Ted Brown ◽  
George E. Houck ◽  
Anna Jeziorowska ◽  
Faye N. Levinson ◽  
Xiaohua Ding ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Fragile X ◽  
Carrier Screening ◽  
Pcr Test

scholarly journals Analysis of unstable DNA sequence in FMR1 gene in Polish families with fragile X syndrome.

1996 ◽  
Vol 43 (2) ◽  
pp. 383-388
Author(s):  
M Milewski ◽  
M Zygulska ◽  
J Bal ◽  
W H Deelen ◽  
E Obersztyn ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
Dna Sequence ◽  
Clinical Features ◽  
Fragile Site ◽  
Fragile X ◽  
Fmr1 Gene ◽  
Repeat Number ◽  
Full Mutation ◽  
Cgg Repeats ◽  
Large Expansion

The unstable DNA sequence in the FMR1 gene was analyzed in 85 individuals from Polish families with fragile X syndrome in order to characterize mutations responsible for the disease in Poland. In all affected individuals classified on the basis of clinical features and expression of the fragile site at X(q27.3) a large expansion of the unstable sequence (full mutation) was detected. About 5% (2 of 43) of individuals with full mutation did not express the fragile site. Among normal alleles, ranging in size from 20 to 41 CGG repeats, allele with 29 repeats was the most frequent (37%). Transmission of premutated and fully mutated alleles to the offspring was always associated with size increase. No change in repeat number was found when normal alleles were transmitted.

FRAGILE X CHROMOSOME: CONSISTENT DEMONSTRATION OF FRAGILE SITE IN FIBROBLAST CULTURES

The Lancet ◽  
1982 ◽  
Vol 319 (8263) ◽  
pp. 101 ◽  
Author(s):  
AnneP. Gardner ◽  
R.T. Howell ◽  
A. Mcdermott
Keyword(s):  
X Chromosome ◽  
Fragile Site ◽  
Fragile X ◽  
Fibroblast Cultures

PRENATAL DIAGNOSIS OF THE FRAGILE X SYNDROME

1986 ◽  
pp. 73-77
Author(s):  
Lawrence R. Shapiro ◽  
Patrick L. Wilmot ◽  
Pauline Brenholz
Keyword(s):  
Prenatal Diagnosis ◽  
Fragile X Syndrome ◽  
Fragile X

Fragile X: A Family of Disorders

2010 ◽  
Author(s):  
Ann M. Mastergeorge ◽  
Jacky Au
Keyword(s):  
Intellectual Disability ◽  
Fragile X Syndrome ◽  
X Chromosome ◽  
Culture Media ◽  
Fragile Site ◽  
Fragile X ◽  
Single Gene ◽  
Repeat Sequence ◽  
Full Mutation ◽  
Tissue Culture Media

Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability known, and it is the most common single gene disorder associated with autism (Belmonte and Bourgeron 2006; Reddy 2005). It is caused by the lack or deficiency of the FMR1 protein, FMRP (Loesch et al. 2004b). The typical physical features of FXS include prominent ears, hyperextensible finger joints, flat feet, soft skin, and in adolescence and adulthood large testicles (macroorchidism) and a long face (Hagerman 2002b). The behavioral features include poor eye contact, hyperarousal to stimuli, anxiety, hyperactivity, attention deficit, impulsivity, hand stereotypies (such as hand biting and hand flapping), and social deficits including autism and autism spectrum disorder (ASD) (Budimirovic et al. 2006; Clifford et al. 2007; Hall et al. 2008b; Hatton et al. 2006b; Sullivan et al. 2007b). Fragile-X syndrome was first reported by Lubs (1969) in two brothers who had intellectual disability and the appearance of a marker X chromosome, which is a fragile site on their X chromosome. It was later detected that this fragile site on the X chromosome only occurred when the chromosomes were studied in a folate-deficient tissue culture media (Sutherland 1977). Therefore cytogenetic studies were utilized to document cases of FXS throughout the 1980s until the Fragile X Mental Retardation 1 gene (FMR1) was discovered in 1991 (Verkerk et al. 1991). The FMR1 gene was found to have a trinucleotide (CGG) repeat sequence at the 5’ untranslated region, with the normal range later determined to be up to 44 repeats, a gray zone of 45–54 repeats, a premutation of 55–200 repeats, and a full mutation range of more than 200 repeats (Maddalena et al. 2001). Those individuals with the full mutation have a deficit or absence of the FMR1 protein (FMRP) that causes the physical, behavioral, and cognitive features of FXS (Loesch et al. 2004b). Females with the full mutation have another X chromosome that is producing FMRP, depending on the activation ratio (AR) or the percentage of cells that have the normal X chromosome as the active X chromosome.

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