Acute post-streptococcal glomerulonephritis in children of French Polynesia: a 3-year retrospective study.

The aim of this study was to define the current demographic, clinical and prognostic characteristics of acute post-streptococcal glomerulonephritis (APSGN) in French Polynesia and to compare these features with those of other populations. Fifty children, all of whom were <15 years old and had been admitted to the Territorial Hospital of Papeete for APSGN between January 2005 and December 2007, were retrospectively enrolled in the study. Diagnostic criteria were microscopic or macroscopic haematuria, decreased C3 fraction of the complement and evidence of recent streptococcal infection. The annual incidence was 18 cases per 100,000 children <15 years of age in 2007. Most of the children (98%) enrolled in the study were of Polynesian ethnic origin, 27 were male (54%), and the average age at presentation was 6.7 years. Signs of previous respiratory infections were clearly evident in 40% of the children. Most of the patients presented during the rainy season, correlating with the relatively high incidence of skin infections at this time. The majority of patients had proteinuria (98%), with 25% having proteinuria in the nephrotic range (proteinuria/urinary creatinine >3 g/g). The presentation was severe in 22% of the children (congestive cardiac failure, severe hypertension and/or encephalopathy), and renal failure was an initial presenting symptom in 43.7%. The C3 fraction was lower in severe presentations, but the type of haematuria, level of proteinuria and inflammatory syndrome were not correlated with immediate severe forms or with initial renal failure. Haematuria resolved in a mean of 7.7 months and proteinuria in a mean of 3.9 months. None of the children had hypocomplementemia for more than 8 weeks. Acute post-streptococcal glomerulonephritis is endemic among French Polynesians, and they can be considered to be a high-risk population. Despite a high incidence of skin infections, however, the predominance of respiratory infections potentially indicates that French Polynesia is on the way to become a low-incidence area. Systematic detection and treatment of group A Streptococcus should be intensified.

First characterization of a large deletion of the PDHA 1 gene.

Pyruvate dehydrogenase complex (PDC) deficiency is one of the major recognized causes of congenital lactic acidosis. The most common form is due to PDHA 1 gene (Xp22.12) defects. Here, we report the case of a Polynesian girl presenting with delayed neurological development, cortical atrophy, and posterior corpus callosum agenesis. Elevated lactate and pyruvate levels in blood and cerebrospinal fluid suggested PDC deficiency. However, PDC activity was within the normal range in lymphocytes and the direct sequencing of the 11 exons and intron-exon junctions of the PDHA 1 gene did not show any changes. Long-range PCR amplification of the whole gene (16 kb) from blood DNA revealed a heterozygous deletion of approximately 4.2kb. Fine mapping of the deletion breakpoint was achieved using purified long-range PCR products for restriction enzyme analysis and direct sequencing. The deletion removed a 4,227 bp region covering part of intron 5 to part of intron 9 [g.10,145_14,371 del 4,227]. The deletion breakpoint contained a short direct repeat (GTAG), which may be derived either from the upstream or the downstream homologous sequence. The presence of a GAG triplet and inverted repeats in the vicinity of the deletion suggest replication slippage at a polymerase alpha arrest site. This is the first time that a large intragenic deletion of the PDHA 1 gene has been characterized.