Furthermore, our results indicate that the G6PD activity and electrophoretic mobility in Fra X males is similar to that in normal cells, thus providing no evidence for the loss of the long-arm telomere in the fragile X syndrome.
This fragile-X syndrome has been shown to be closely linked also to a Taq I restriction fragment length polymorphism detected by a cDNA probe for factor IX, and the latter locus has been mapped to the subtelomeric region Xq26-Xq28 [Camerino, G., Mattei, M. G., Mattei, G. F., Jaye, B.
At the 1983 NIH workshop on XLMR there was a general consensus that a connective tissue dysplasia is a component of the Martin-Bell syndrome, a fact since confirmed by others on the basis of objective measurements of finger joint hypermobility and frequent presence of mitral valve prolapse.
This indicates that the genetic distance between the Factor IX gene and the fra(X) locus is too great for Factor IX probes to be used alone for carrier detection in the fra(X) syndrome.
We have performed a linkage analysis in 16 families between the locus for the fragile-X syndrome, FRAXQ27, and two polymorphic DNA markers that correspond to the anonymous probe St14 and to the coagulation factor IX gene F9.
However, the possibility exists that the common fragile site at Xq27 may be the substrate for unequal recombination events that produces the rare fragile site associated with Martin-Bell syndrome.
Such a segregation distortion is difficult to assess for the fra(X) syndrome because of incomplete penetrance, variable expression and probable ascertainment biases.
The still debated question of whether the expression of mental retardation in heterozygous carriers of the Martin-Bell syndrome is influenced by X inactivation has been investigated in a group of phase-known double heterozygotes for the FRA-X mutant and the G6PD Mediterranean variant.
The still debated question of whether the expression of mental retardation in heterozygous carriers of the Martin-Bell syndrome is influenced by X inactivation has been investigated in a group of phase-known double heterozygotes for the FRA-X mutant and the G6PD Mediterranean variant.
The still debated question of whether the expression of mental retardation in heterozygous carriers of the Martin-Bell syndrome is influenced by X inactivation has been investigated in a group of phase-known double heterozygotes for the FRA-X mutant and the G6PD Mediterranean variant.
Identification of a gene (FMR-1) containing a CGG repeat coincident with a breakpoint cluster region exhibiting length variation in fragile X syndrome.
To study the involvement of the FMR-1 gene in the fragile X syndrome, its expression was studied in lymphoblastoid cell lines and leukocytes derived from patients and normal controls.
Localization of the brain-expressed FMR-1 gene to this EcoRI fragment suggests the involvement of this gene in the phenotypic expression of the fragile X syndrome.
Localization of the brain-expressed FMR-1 gene to this EcoRI fragment suggests the involvement of this gene in the phenotypic expression of the fragile X syndrome.
To study the involvement of the FMR-1 gene in the fragile X syndrome, its expression was studied in lymphoblastoid cell lines and leukocytes derived from patients and normal controls.
Localization of the brain-expressed FMR-1 gene to this EcoRI fragment suggests the involvement of this gene in the phenotypic expression of the fragile X syndrome.
To study the involvement of the FMR-1 gene in the fragile X syndrome, its expression was studied in lymphoblastoid cell lines and leukocytes derived from patients and normal controls.
A large Sardinian family including 13 Martin-Bell syndrome (MBS) patients, several instances of normal transmitting males or females, and the G6PD-Mediterranean mutant segregating in some of its branches, has been thoroughly investigated with the hope of gaining further insight on the nature of the FRAX-mutation.
Linkage data using the markers F9 (factor IX), DXS105 (cX55.7), DXS98 (4D-8), DXS52 (St14), DXS15 (DX13), and DXS134 (cpX67) are presented from 26 pedigrees segregating with fragile X (fra[X]) syndrome.