Variante juvenil de la enfermedad de Sandhoff: presentación del primer caso descrito en Argentina / Juvenile form of Sandhoff disease: first case reported in Argentina

La enfermedad de Sandhoff es una patología neurodegenerativa, de almacenamiento lisosomal, causada por mutaciones en el gen HEXB. Existen tres formas clínicas: infantil, juvenil y adulta. Previamente, fue identificada una población endogámica en la provincia de Córdoba, Argentina, que presentaba una alta incidencia de la enfermedad; todos los casos correspondieron a la forma infantil. En este trabajo, se presenta por primera vez el caso de un paciente argentino con la variante juvenil de la enfermedad de Sandhoff. El paciente es un niño de 7 años que, a partir de los 2, presentó ataxia, trastorno del habla y retraso global en el desarrollo. El diagnóstico se confirmó con la detección de valores residuales de enzima hexosaminidasa y con la identificación de dos mutaciones ya descritas en estado de heterocigosis: c.796T>G (p.Y266D) y c.1615C>T (p.R539C).

Sandhoff disease is a neurodegenerative, lysosomal and autosomal recessive disease caused by mutations in the HEXB gene. Three forms are recognized: infantile, juvenile and adult. Previously, an endogamous population in Córdoba, Argentina, was identified with a high incidence of Sandhoff disease, all reported cases were of the infantile type. In this work, we describe a child with the juvenile form of Sandhoff disease, the first case reported in Argentina. The patient is a 7-year-old boy presenting with ataxia, speech disturbances and global developmental delay, symptoms starting at the age of 2 years. Diagnosis was based on the hexosaminidase deficiency. Sequencing of genomic DNA revealed compound heterozygosity for two HEXB gene mutations: c.796T>G (p.Y266D) and c.1615C>T (p.R539C), both already reported.

An analysis of multiplex-PCR in the detection of BCR-ABL transcripts in hematological disorders

In this work, we describe the advantages of multiplex-PCR in the specific detection of BCR-ABL transcripts in different hematological disorders and its sensitivity compared to nested PCR. Fifty-three patients were studied for the presence of BCR-ABL transcripts: 24 patients with chronic myeloid leukemia (CML), 20 with acute leukemia (AL), and 9 patients with other hematological disorders. A variant rearrangement (b3a3) was found in a single case of CML (4.2 percent). Four out of the 20 patients with AL (20.0 percent) (14 adults, 6 children) were bcr-abl(+), and in this group three cases were classified as B-acute lymphoblastic leukemia (B-ALL), and one as acute myeloblastic leukemia (AML). Two of the three patients with B-ALL were positive for b2a2 and the other one for e1a2, while in the BCR-ABL(+)AML patients a b3a2 rearrangement was observed. In conclusion, multiplex-PCR allows rapid, specific and simultaneous detection of different types of BCR-ABL transcripts in CML and ABL-BCR(+)AL. A full correlation was observed when multiplex-PCR was compared with nested PCR.

Cystic fibrosis: frequency of delta F508 and G542X mutations in Córdoba, Argentina

Using Polymerase Chain Reaction (PCR) based techniques we analyzed the frequency and genotypic distribution of two mutations (deltaF5O8 and G542X) that produce Cystic Fibrosis. The study was carried out in 19 non-related patients (38 chromosomes) born in the Province of Córdoba. The distribution of genotypes showed the presence of 8 homozygote patients deltaF5O8/deltaF5O8, 2 individuals with non-determined mutations (X/X) and 9 compound heterozygotes (deltaF5O8/X). The mutation G542X was not found. The mutation deltaF5O8 was detected in 25 chromosomes resulting in an incidence of 66 por ciento.