RESUMEN
Spinal muscular atrophy (SMA) is the second most common lethal autosomal recessive disorder. It is divided into the acute Werdnig-Hoffmann disease (type I), the intermediate form (type II), the Kugelberg-Welander disease (type III), and the adult form (type IV). The gene involved in all four forms of SMA, the so-called survival motor neuron (SMN) gene, is duplicated, with a telomeric (tel SMN or SMN1) and a centromeric copy (cent SMN or SMN2). SMN1 is homozygously deleted in over 95% of SMA patients. Another candidate gene in SMA is the neuronal apoptosis inhibitory protein (NAIP) gene; it shows homozygous deletions in 45-67% of type I and 20-42% of type II/type III patients. Here we studied the SMN and NAIP genes in 92 Algerian SMA patients (20 type I, 16 type II, 53 type III, and 3 type IV) from 57 unrelated families, using a semiquantitative PCR approach. Homozygous deletions of SMN1 exons 7 and/or 8 were found in 75% of the families. Deletions of exon 4 and/or 5 of the NAIP gene were found in around 25%. Conversely, the quantitative analysis of SMN2 copies showed a significant correlation between SMN2 copy number and the type of SMA.
RESUMEN
The incidence of infantile visceral leishmaniasis is currently increasing, at least in the Mediterranean region. Most cases seen in France occur on the Mediterranean coast or are imported from Africa. However, contamination in other regions of France is not an exceptional occurrence and may raise diagnostic problems. The parasite reservoir is the dog population in which the prevalence of Leishmania infection is particularly high in the Provence and Cévennes regions. Both teenagers and young children may be affected by this disease, whose clinical manifestations may be misleading. The typical symptomatic triad, i.e., anemia-fever-enlarged spleen, may be incomplete, especially as a result of the intermittent character of the fever. Patients may remain afebrile for long periods. Diagnosis rests on demonstration of the parasite in bone marrow specimens (several biopsies are often required) or in the spleen. Bacteriologic studies using a special medium are helpful. Serologic tests are sensitive and specific but often become positive only late in the disease. Management still rests on pentavalent antimonial compounds. Advances have been made in the understanding of the toxic effects and rules for optimal use of these drugs. Improved insight into the parasite's biology may result in use of new forms of treatment; allopurinol is at present the only recent addition to the armamentarium which has been proved effective in humans when given in combination with an antimonial compound.