[Nephronophtisis in Senegal: first 3 cases].

Nephronophtisis is a familial tubulo-interstitial nephropathy with an autosomic recessive mode of transmission. To our knowledge, it has not been yet reported in Black Africa. We report here the case of a 17-year old female from Senegal who presented with renal failure related to a chronic interstitial nephritis characterized by polyuria, hypocalcemia, natriuresis of 23 mmol/l and serum creatinine level of 1070 mumol/l. The parents of this patient were first-degree cousins. Among the 6 siblings, 2 other males were found to have a renal disease. Ultrasound examination of the kidneys showed medullary cysts in the 2 affected brothers and the renal biopsy in one case showed tubular atrophy, with thickening of the basal lamina and an interstitial fibrosis without glomerular involvement. Molecular genetic analysis confirmed the diagnosis of nephronophtisis, with a homozygous deletion of the NPH1 region. In order to recognize this disease early in life, one has to look for it in patients with tubulo-interstitial nephritis, polyuria, childhood enuresia especially when it is associated with growth retardation or tetany. This case raises the issue of consanguinity and endogamy which are frequently encountered in Africa. It also extends the geographic and ethnic distribution of nephronophtisis, being the first cases reported Black Africans.