In:
European Journal of Endocrinology, Oxford University Press (OUP), Vol. 164, No. 2 ( 2011-02), p. 295-301
Abstract:
Pseudohypoparathyroidism (PHP) is a heterogeneous disorder characterized by hypocalcemia and hyperphosphatemia resulting from selective renal resistance to parathyroid hormone (PTH). One autosomal dominant form of PHP type 1b (PHP-Ib) is most frequently caused by a maternally inherited 3-kb deletion within STX16 , the gene encoding syntaxin 16. To date, increased bone mineral density (BMD) has been described only in PHP type 1a, and there is a lack of detailed information on bone histomorphometry in PHP-Ib. The objective of this report was to present trans-iliac static and dynamic histomorphometry in two brothers with the 3-kb deletion in the STX16 region and elevated BMD. Design Observational study of two brothers (age 18.0 and 22.7 years) with the 3-kb STX16 deletion and increased BMD. Results The brothers had elevated PTH (146 pg/ml (15.6 pmol/l) and 102 pg/ml (10.9 pmol/l); normal: 10–64 pg/ml (1.1–6.8 pmol/l)) and striking osteosclerosis (lumbar spine areal BMD Z -scores: +5.4 and +4.9). Bone histomorphometry showed marked elevations in cortical width for both brothers (241 and 209% of the mean result expected for age), with elevations in the bone formation rate on the endocortical (119 and 260% of the healthy mean) and trabecular (220 and 190% of mean) surfaces. Conclusion Our findings suggest that PTH in this PHP-Ib genotype can increase cortical thickness due to its anabolic effect on endocortical bone, and underscore the heterogeneity in the skeletal phenotype among patients with PHP-Ib.
Type of Medium:
Online Resource
ISSN:
0804-4643
,
1479-683X
Language:
Unknown
Publisher:
Oxford University Press (OUP)
Publication Date:
2011
detail.hit.zdb_id:
1485160-X
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