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25-hydroxyvitamin D [25(OH)D] may not optimally indicate vitamin D receptor activity. Higher concentrations of its catabolic product 24,25-dihydroxyvitmin D [24,25(OH)2D] and a higher ratio of 24,25(OH)2D to 25(OH)D (the vitamin D metabolite ratio [VMR]) may provide additional information on receptor activity. We compared the strength of associations of these markers with serum PTH concentrations, hip bone mineral density (BMD), and risk of incident hip fracture in community-living older participants in the Cardiovascular Health Study. Among 890 participants, the mean age was 78years, 60% were women, and the mean 25(OH)D was 28±11ng/ml. In cross-sectional analysis, the strength of association of each vitamin D measure with PTH was similar; a 1% higher 25(OH)D, 24,25(OH)2D, and VMR were associated with 0.32%, 0.25%, and 0.26% lower PTH, respectively (p<0.05 for all). Among 358 participants with available BMD data, we found no associations of 25(OH)D or VMR with BMD, whereas higher 24,25(OH)2D was modestly associated with greater hip BMD (1% higher 24,25(OH)2D associated with 0.04% [95% CI 0.01-0.08%] higher BMD). Risk of incident hip fracture risk was evaluated using a case-cohort design. There were 289 hip fractures during a mean follow up time of 8.4years. Both higher 24,25(OH)2D and VMR were associated with lower risk of hip fracture (HR per SD higher, 0.73 [0.61, 0.87] and 0.74 [0.61, 0.88], respectively) whereas 25(OH)D was not associated with hip fracture (HR 0.93 [0.79, 1.10]). We conclude that evaluating vitamin D status by incorporating assessment of 24,25(OH)D and the VMR provides information on bone health above and beyond 25(OH)D alone.

De satijn cavia is in de tachtiger jaren vanuit Noord Amerika naar Europa gekomen en al vanaf het begin van zijn bestaan is het ras geplaagd door allerlei rasgebonden problemen. Osteo distrofie (OD) is een chronische en progressieve ziekte die geleidelijk aan steeds pijnlijker wordt. Alhoewel OD hoofdzakelijk bij satijn cavia's wordt vastgesteld, komt de ziekte ook voor bij andere rassen

We recently studied a patient who meets criteria for autistic disorder and has a 2q37 deletion. Molecular cytogenetic studies were carried out using DNA isolated from 22 different 2q37 mapped BACs to more precisely define the extent of the chromosome deletion. We also analyzed 2q37 mapped polymorphic markers. In addition DNA sequences of BACs in the deletion region were scanned to identify microsatellite repeats. We describe four new polymorphic microsatellite repeat markers in the 2q37.3 region. These markers enabled us to determine the parental origin of the deletion in our patient. DNA from 8-13 unrelated individuals was used to determine heterozygosity estimates for these markers. We review four genes deleted in our patient - genes whose known functions and sites of expression in the brain and/or bone make them candidates for involvement in autism and/or the osteodystrophy observed in patients with 2q37.3 deletions.

We recently studied a patient who meets criteria for autistic disorder and has a 2q37 deletion. Molecular cytogenetic studies were carried out using DNA isolated from 22 different 2q37 mapped BACs to more precisely define the extent of the chromosome deletion. We also analyzed 2q37 mapped polymorphic markers. In addition DNA sequences of BACs in the deletion region were scanned to identify microsatellite repeats. We describe four new polymorphic microsatellite repeat markers in the 2q37.3 region. These markers enabled us to determine the parental origin of the deletion in our patient. DNA from 8-13 unrelated individuals was used to determine heterozygosity estimates for these markers. We review four genes deleted in our patient - genes whose known functions and sites of expression in the brain and/or bone make them candidates for involvement in autism and/or the osteodystrophy observed in patients with 2q37.3 deletions.