Quantitative ultrasound of the hand phalanges in patients with genetic disorders: a pilot case-control study.

Skeletal status in subjects with genetic disorders rarely has been a matter of interest, and the risk for osteoporotic fracture in this population is not known. The aim of this study was to estimate ultrasound values in subjects with genetic disorders. In the study 50 patients (36 boys and 14 girls, mean age 11.8 +/- 2.9 years) and 528 healthy controls matched for age and body size (380 boys and 148 girls, mean age 11.9 +/- 2.5 years) were evaluated. Patients with the following disorders were included: Down syndrome, Martin-Bell syndrome, Marfan-Mass phenotype and others. Bone status was assessed by quantitative ultrasound (QUS) of hand phalanges using DBM Sonic 1200 (IGEA, Carpi, Italy), which measures amplitude-dependent speed of sound (Ad-SoS, m/s). Ad-SoS was significantly lower in patients than in controls (in the whole group 1,915 +/- 69 m/s vs. 1,970 +/- 62.0 m/s, P<0.0000001; in males 1,917 +/- 73 m/s vs. 1,972 +/- 63 m/s, P<0.000001; in females 1,910 +/- 58 m/s vs. 1,963 +/- 58 m/s, P<0.01). Ad-SoS correlated significantly with age and body size (except for Ad-SoS with age in female patients). In all subgroups of patients (except for the subjects with Marfan-Mass syndrome) Ad-SoS values were significantly lower than in controls. In a multiple, stepwise regression analysis of Ad-SoS on age and body size, in the whole group of patients age and height had significant influence on Ad-SoS, and in controls age, height and weight. In conclusion, the study shows significantly lower phalangeal ultrasound values in subjects with different genetic disorders compared to normal healthy persons.