Background: Renal tubular acidosis (RTA) is an uncommon cause of growth failure and rickets. In Haiti, diagnostic evaluation and management is challenged by limited access to comprehensive diagnostic tools.
Case presentation: An 8-year-old Haitian girl was evaluated at an academic referral center for bony deformations and bone pain, progressive over the previous six years. Her 2.5 year-old sister presented similar symptoms, associated with dental caries and inability to walk for the past 6 months. There was no history of bone deformation in the family, and no parental consanguinity. Both siblings were exclusively breastfed for six months and were since consuming a balanced diet. Neither was taking any medications and they were adequately exposed to sunlight. On exam, weight and height were 17.2 kg (−3 standard deviation scores (SDS)) and 99 cm (−5.6 SDS) in the older, and 9.8 kg (−3 SDS) and 77 cm (−3 SDS) in the younger sibling. Mild Kussmaul breathing was evident. Both had a sawtooth enamel and multiple dental caries, asymmetrical chests, costal rosary, distended abdomen, wide wrist, epiphyseal beads, multiple bone deformity, the older had a waddling gait and bilateral genu valgus. Remainder examination, including cognitive development, was normal. Laboratory testing in the older sibling revealed non-anion gap metabolic acidosis (bicarbonate 9 mmol/l) with alkaline urine (pH 9.3), 1+ proteinuria but no glycosuria, hypophosphatemia (phosphorus 2.8 mg/dl), hyperphosphatasia (alkaline phosphatase 880 U/l), normal values for total calcium, 25-OH-vitamin D, parathyroid hormone, serum albumin, BUN, and creatinine. Radiographic findings were consistent with severe rickets. Results were similar in the younger sibling.
Conclusion: We present the first cases of severe growth delay and rickets due to RTA in a sibling pair in Haiti. While detailed evaluation and genetic testing was unavailable, a clinical diagnosis was possible and allowed for initiation of therapy with oral bicarbonate.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology