Early treatment of familial hypophosphataemic rickets.

Abstract

Evidence for an unidentified steroid in a child with apparent mineralocorticoid hypertension. J Clin Endocrinol Metab 1977;44:924-33. 4 Case report A girl, aged 2-years at the time of this report, had been observed since birth. Her mother was known to have a sporadic form of HR with severe bone abnormalities (osteomalacia) and dwarfism, and had been treated during infancy with combined phosphates and vitamin D3 without any improvement. The pregnancy was normal, and a caesarean section was performed for maternal indications.Our patient's birthweight was 3-3 kg and her length was 52 cm. A physical examination at age 2 months showed her to be normal-weight and height at the 25th centile. Laboratory investigations at that time found the following: hypophosphataemia-phosphate 1 13 mmol/l (3 5 mg/dl), normal range for our laboratory I 29-2-09 mmol/l; normal serum calcium 2-23 mmol/l (9-2 mg/dl), normal range 2-1-2-6 mmol/l; raised alkaline phosphatase-56 KA units, normal range 7-5-32*5 KA units; hypocalciuria-0 0365 mmol/kg/24 hours (1 46 mg/kg/24 hours); hyperphosphaturia-45-54 mmol/l 73m2/24 hours (1 41 mg/ 173m2/24 hours); and a reduction in renal tubular reabsorption of phosphate-60 %.

Early Treatment Improves Growth and Biochemical and Radiographic Outcome in X-Linked Hypophosphatemic Rickets

“…Anecdotal case reports suggest that initiation of therapy in infancy, before the development of severe growth deficit and manifest rickets, may lead to more satisfactory results than treatment commenced later (11)(12)(13). Lapatsanis et al (12) reported two children who were treated from age 6 wk; their heights at the ages of 26 and 60 months were just below the 50th percentile, and the rachitic lesions in x-rays remained absent or were mild.…”

“…Therefore, initiation of treatment during early infancy, before overt manifestation of rickets and growth retardation, would be expected to result in improved height gain compared with the effect of treatment commenced at a later time. Anecdotal case reports are indeed suggestive of this (11)(12)(13), but no long-term studies to final height have previously been published.…”

Early Detection of Infants with Hypophosphatemic Vitamin D Resistant Rickets (HDRR).

“…There are, however, only a few reports on the early biochemical and radiographic findings in familial HDRR [4][5][6][7]. Schoen et al and Moncrieff reported that hypophosphatemia develops by age 2 months and rachitic changes develop by age 6 months [4,7].…”

X-linked hypophosphatemic rickets without ?rickets?

“…However, they did not specify which bones were examined nor the frequency of this finding. In contrast, other reports have generally attributed the absence of rickets to the age of the patient (less than 2 years) and the absence of weight-bearing [12,16]. Indeed, many investigators consider the presence of rickets an important criterion in establishing the diagnosis of X-linked hypophosphatemia in patients older than 2 years of age.…”