Fluctuating asymmetry (FA) of 8 morphometric traits was studied in 113 preterm infants (26-36 wk of gestation), 103 term infants (37-41 wk), and their respective parents. With 3 different measures of FA, the highest values were obtained from extremely preterm infants (26-29 wk), and the lowest from the group of term infants. The estimates of FA values among parents, particularly mothers, showed a similar, albeit less pronounced, trend. Multiple regression analysis of individual mean FA values, calculated in infants for the 8 studied bilateral traits, documented a significant inverse correlation with gestational age and with the health status of the infants and their mothers, as well as a positive correlation with the mothers' mean FA values.

The complex segregation analyses performed in our previous studies revealed a significant major gene (MG) effect on the age-adjusted cortical and cancellous bone mineral density (BMD) in two ethnically different populations, Chuvasha and Turkmenians. The aim of the present study was to test the hypothesis of pleiotropic MG control of three components of bone aging, that is, the baseline level of BMD ( gs ), the age at onset of the bone mass loss (T gs ), and the rate of this loss over the years (␣ gs ). Nuclear and more complex pedigrees from the same two ethnic samples were assessed for hand phalangeal BMD (Chuvasha, 1208 individuals, and Turkmenians, 643 individuals), and complex segregational analysis incorporating age and sex effects directly into MG penetrance function was carried out. The results of the present analysis clearly confirmed the existence of the putative MG and showed that the proportion of BMD variation attributable to this MG effect within the sex was remarkably similar in both populations and ranged between 34.7% and 35.2%. The most parsimonious model for BMD transmission in Chuvasha pedigrees additionally indicated significant residual correlation between siblings and clear sex differences in the annual rates of bone loss ␣ gs . The latter was more than twice as high in females than that in males (0.086 SD vs. 0.033 SD per year). In Turkmenian pedigrees the most parsimonious model presented obvious evidence of the MG control of BMD baseline levels in both sexes with significantly lower baseline levels and younger age at onset (T gs ) in females. No clear MG effects were inferred on T gs and/or ␣ gs in either sample, either in males or in females. That is, the present study does not suggest MG ؋ SEX ؋ AGE interaction. We suppose that if the rate of age-related changes in phalangeal BMD is genetically determined, then these are not the same genes as those affecting the BMD baseline levels. (J Bone Miner Res 2002;17:152-161)

Pedigree samples were collected from five ethnically and geographically different populations : Kirghizians, Turkmenians, Chuvashians, Israelis and Mexicans. All studied individuals were assessed for body height, weight and BMI. The sample size in the studied pedigrees ranged from 381 to 1811 individuals. Segregation analysis of these traits preliminarily adjusted for sex and age was performed by means of program package  that provides parameter estimates for the major gene effects, for the residual within the genotype correlations between relatives and for the assortative mating. By the usual transmission probability tests, the ' environmental ' model was strongly rejected for all measured traits in all 5 populations. The major gene mode of inheritance, however, was accepted for all traits. The results of analysis in 5 populations were remarkably similar, and showed that except for Mexican sample, the proportion of variance attributable to major gene effect ranged between 37 and 53 % for body weight and height. In the Mexican sample it explained only about 14 % of the body weight variation. The proportion of inter-individual variation in BMI attributable to major gene effect was consistently lower in all populations in comparison with height and weight and ranged between 17 and 40 %. Strong assortive mating in body height, as estimated by correlation between putative major gene genotypes in spouses, was found in four populations, not including Mexican pedigrees. In spite of the fact that human body height, weight and other anthropometric characteristics became the subject of quantitative genetics almost from the beginning of the present century, very little is known regarding the involvement of large-effect genes in their mode of inheritance, except for body mass index (BMI) and various measures of obesity (e.g. Comuzzie et al. 1995 ; Lecomte et al. 1997).The heritability estimates obtained in standard genetic investigations, utilizing variance

The most frequent site of osteoarthritis (OA) is the hands, but the pattern of hand OA development remains controversial. Understanding these patterns may assist in evaluating biological aging, determining etiology, and proposing ways of preventing hand OA. We investigated the pattern distribution of OA in hands and the influences of age, sex, and handedness on its development. The study population was comprised of Chuvashians (660 males age 18-89 years and 585 females age 18-90 years). OA development was evaluated for 15 joints of each hand according to the Kellgren and Lawrence grading scheme. Statistical analyses included Pearson correlation, cluster analysis, MANCOVA, and linear and polynomial regression. OA changes first appeared in subjects <30 years of age. Metacarpophalangeal (MP) joints underwent the first OA changes until the sixth decade, when the row of distal interphalangeal (DIP) joints became most affected. Cluster analysis showed that symmetry was the most common pattern of interrelationship between rows of joints. The best-fitting and most parsimonious model of age-related pattern of hand OA was the polynomial two-interval linear model. It showed a higher rate of OA development during the relatively young ages, 32-34 years than later on. We found statistically significant differences between sexes only for the DIP (P = 0.019) and PIP (P = 0.011) rows of joints. Handedness had no influence on hand OA development.

A significant genetic component is involved in inter-individual variation and covariation of various studied craniofacial traits.