SHOX Duplication and Tall Stature in a Patient with Xq Deletion and Vascular Disease.

The anomalies of X chromosome are classified as numerical or structural. Concomitant structural anomalies in this chromosome that associate partial loss of its long arm with duplications in its short arm are uncommon. Only a few cases have been published and in most of them the reported patients present ovarian dysfunction, tall stature, and overdosage of the SHOX gene with locus Xp22.33. Considering these reports, we evaluated the case of a woman with a deletion in the long arm of the X chromosome, premature ovarian failure, tall stature, and multiple arterial vascular disease. With the aim to find a relationship between karyotype and phenotype, we explored associated anomalies in Xp and certified the overdosage of the SHOX gene in this case by MLPA. Also, taking into account the fact that the gene locus of the angiotensin-converting enzyme type 2 (ACE2) is located in Xp, our goal was to investigate the influence of this gene in the development of cardiovascular disease. The detection of the gene product of ACE2 by ELISA was undetectable. We have proposed that cytogenetic anomalies in X chromosome could contribute to decrease this protein synthesis in this gender.

Detection of deletions and duplications in the Duchenne muscular dystrophy gene by the molecular method MLPA in the first Argentine affected families.

Deletions/duplications in the Duchenne muscular dystrophy (DMD) gene account for 60 to 70% of all alterations. A new technique, multiplex ligation-dependent probe amplification (MLPA), has been described that allows the detection of large genetic rearrangements by simultaneous amplification of up to 45 target sequences. The present article is based on the diagnosis of the first Argentine affected families by the application of MLPA. DNA samples from patients with and without a previous diagnosis were included. MLPA assays were performed according to manufacturer recommendations. Polymerase chain reaction and direct sequencing were performed when a single-exon deletion was detected. Results were analyzed using the Gene Marker v1.6 and Sequencing Analysis v5.2 software. In the samples with a previous diagnosis (as identified by short tandem repeat-polymerase chain reaction analysis), MLPA confirmed in some samples the same deletion and detected in others a larger deleted fragment. This enabled the prediction of the expected male phenotype. One deletion and one duplication were detected in patients without previous diagnosis. In this study, we investigated the applicability of MLPA in our country. Our results showed a 100% confirmation of the deleted fragments detected by short tandem repeat segregation analysis. Moreover, in some cases, the MLPA assay was able to refine the breakpoints involved. In addition, MLPA identified deletions/duplications in samples without previous diagnosis. In comparison to the available diagnosis strategies in Argentina, MLPA is less time-consuming, and spans the complete coding region of DMD. The application of MLPA will improve the genetic diagnosis of DMD/Becker muscular dystrophy in our country.

Detection of deletions and duplications in the Duchenne muscular dystrophy gene by the molecular method MLPA in the first Argentine affected families

Deletions/duplications in the Duchenne muscular dystrophy (DMD) gene account for 60 to 70% of all alterations. A new technique, multiplex ligation-dependent probe amplification (MLPA), has been described that allows the detection of large genetic rearrangements by simultaneous amplification of up to 45 target sequences. The present article is based on the diagnosis of the first Argentine affected families by the application of MLPA. DNA samples from patients with and without a previous diagnosis were included. MLPA assays were performed according to manufacturer recommendations. Polymerase chain reaction and direct sequencing were performed when a single-exon deletion was detected. Results were analyzed using the Gene Marker v1.6 and Sequencing Analysis v5.2 software. In the samples with a previous diagnosis (as identified by short tandem repeat-polymerase chain reaction analysis), MLPA confirmed in some samples the same deletion and detected in others a larger deleted fragment. This enabled the prediction of the expected male phenotype. One deletion and one duplication were detected in patients without previous diagnosis. In this study, we investigated the applicability of MLPA in our country. Our results showed a 100% confirmation of the deleted fragments detected by short tandem repeat segregation analysis. Moreover, in some cases, the MLPA assay was able to refine the breakpoints involved. In addition, MLPA identified deletions/duplications in samples without previous diagnosis. In comparison to the available diagnosis strategies in Argentina, MLPA is less time-consuming, and spans the complete coding region of DMD. The application of MLPA will improve the genetic diagnosis of DMD/Becker muscular dystrophy in our country.