Biomedical subjects

M A Alliende

Publications and source records attributed to M A Alliende.

7 recordsLinked to original sources

PubMed2001

[Molecular diagnosis of Prader-Willi and Angelman syndromes: methylation, cytogenetics and FISH analysis].

BACKGROUND: The diagnosis of Prader-Willi and Angelman syndromes is difficult, since their phenotypic manifestations are variable and unspecific. The study of the methylation state of DNA in 15(q11-q13) using polymerase chain reaction, called methylation test, allows the diagnosis of most patients with Prader-Willi and Angelman syndromes, irrespective if the underlying molecular alteration is a deletion, uniparental disomy or a punctual imprinting mutation. AIM: To assess the effectiveness of methylation test in the diagnosis of Prader-Willi and Angelman syndromes. PATIENTS AND METHODS: Thirty seven cases with a presumptive diagnosis of Prader-Willi syndrome and 25 with the presumptive diagnosis of Angelman syndrome were studied. Methylation test was done in genomic DNA obtained from peripheral lymphocytes. RESULTS: Methylation test confirmed the clinical diagnosis in 11 of 37 patients with Prader Willi (30%) and 6 of 25 patients with Angelman syndrome (24%). CONCLUSIONS: Clinical criteria overestimate the diagnosis of Prader-Willi and Angelman syndromes. The initial diagnosis should be confirmed with the methylation test and, if necessary, with FISH that will detect most deletions in the region.

Adolescent↗

PubMed1998

[Direct molecular analysis of FMR-1 gene mutation in patients with fragile Xq syndrome and their families].

BACKGROUND: The unequivocal diagnosis of fragile Xq syndrome is based in the direct analysis of the underlying FMR-1 gene mutation, that consists in an increased number of trinucleotide CGG repetitions. AIM: To study families with fragile Xq syndrome, using the Southern technique for the analysis of the mutation. SUBJECTS AND METHODS: Fifteen individuals, pertaining to 6 families with fragile Xq syndrome, were studied. Clinical, cytogenetic and molecular analysis using Southern technique, were done. RESULTS: Five male individuals had a clinically evident syndrome, confirmed by cytogenetic analysis that showed fragility in 10 to 29% of studied cells. One subject with a clinical picture suggesting fragile Xq had a normal cytogenetic study. The other studied subjects were the mothers of the five subjects with the syndrome, that must be carriers, and four brothers. Molecular analysis showed that seven subjects (5 males) had a complete mutation, five (4 females) were carriers of a pre mutation and three (2 males) did not have the mutation. CONCLUSIONS: The Southern technique allows to verify the normal condition of FRAXA locus, identify carriers and to detect complete mutations in fragile Xq syndrome.

Female↗

PubMed1984