[The molecular genetics of the fragile X syndrome. Its molecular diagnosis by DNA probes].
BACKGROUND
The cytogenetic analysis of the fragile X affected shows a break point in the q27.3 region of chromosome X. However many carrier females and normal carrier males remain refractory to cytogenetic diagnosis. New DNA probes tightly linked to the fragile X point are now available allowing by the familiar RFLP analysis to detect the carrier members.


METHODS
Fragile X syndrome affected families were studied cytogenetically and by the use of DNA probes flanking the fragile X region: 1A1, U6.2, VK21 in the distal region and RN1, 4D-8, cX55.7 in the proximal.


RESULTS
The haplotypes from two X fragile syndrome affected families were obtained. These families were informatives for all the DNA probes used. The cytogenetic results obtained agree with the previously inheritance pattern reported.


CONCLUSIONS
It is very important to detect the normal male carriers. The determination in one family of the origin of the fragile X mutation is possible by the use of DNA probes.
Giné
R
R
Centro de Investigación y Desarrollo, Hospital de la Seguridad Social de Las Palmas.
Espinás
M L
ML
Antich
J
J
Carballo
M
M
D002871:Chromosome Banding; D002873:Chromosome Fragility; D004247:DNA / Q000302:isolation & purification; D015342:DNA Probes; D004587:Electrophoresis, Agar Gel; D005600:Fragile X Syndrome / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D008297:Male; D010375:Pedigree; D010761:Phosphorus Radioisotopes
D015342:DNA Probes; D010761:Phosphorus Radioisotopes; D004247:DNA
Genética molecular del síndrome del cromosoma X frágil. Diagnóstico molecular mediante sondas de ADN.