Introduction: Primary hyperoxaluria type 1 (PH1) is the most frequent and severe form of primary hyperoxalurias. It is a rare autosomal recessive disease caused by an enzymatic deficiency in alanine-glyoxylate aminotransferase (AGT). Autosomal dominant polycystic kidney disease (ADPKD) is a hereditary condition characterized by the development in adulthood, but in 72% of cases during the second decade, of multiple cysts in the kidneys and very often in the liver. It is the most common hereditary renal disease worldwide.

Patients and Methods: Patient M.S., an 11-year-old boy from a first-degree consanguineous marriage, only son of two siblings originating from northern Algeria, with a family history of a sister and mother affected by ADPKD, diagnosed at 12 and 20 years respectively. The child consulted for bilateral renal colic associated with recurrent urinary tract infections beginning at the age of two years with stone expulsion. Clinical examination revealed a child in good general condition, no growth retardation, normal blood pressure at 110/70 mmHg, polyuria greater than 3 L/day. Urinalysis showed morning pH at 5.5, the rest without abnormalities. Laboratory blood and urine tests including complete blood count, renal function, serum electrolytes, calcium-phosphorus, liver and lipid profiles were normal. Calciuria was 1.08 mmol/L and hyperoxaluria was 449 mmol/L. The crystalline composition of expelled stones was whewellite (calcium oxalate monohydrate). Morphological assessment with plain abdominal X-ray and abdominopelvic ultrasound revealed nephrocalcinosis. Molecular analysis was performed by direct sequencing of exons 1, 4, 7, and 10 of the AGXT gene. The proband was homozygous for the c.853C>T (p.Ile244Thr) mutation, known as the "Maghrebian" mutation [Nagara et al., 2013; Belhaj et al., 2011]. Both parents were heterozygous for this mutation, and the sister did not carry the mutation. The child was started on diuretic therapy and pyridoxine at 500 mg/day, with significant improvement in oxalemia and oxaluria levels measured one year later.

Discussion and Conclusion:

 This is a first-degree consanguineous family presenting two hereditary renal diseases that can lead to extrarenal replacement therapy. A detailed literature review on the Maghrebian mutation of PH1 and the studied populations [Nagara et al., 2013; Belhaj et al., 2011], as well as the rare observations of an association of two genetic renal diseases described in the same family, was performed. The dual hereditary renal involvement in this family posed the problem of genetic counseling and living-related renal transplantation. As the mother and sister have ADPKD, they cannot serve as kidney donors. The father remains the only potential donor. The development of cadaveric organ transplantation in our country remains the only hope for this family.