Difference in height associated with a translation start site polymorphism in the vitamin D receptor gene

Vitamin D Receptor Gene Polymorphisms in Serbian Patients With Bronchial Asthma: A Case-Control Study

Vitamin D and single nucleotide polymorphisms (SNPs) in vitamin D receptor (VDR) gene are potentially involved in the pathogenesis of bronchial asthma (BA); however, precise mechanisms by which vitamin D reduces the inflammation and the role of VDR SNPs in BA are not completely understood. The aim of this study was to examine the possible associations of FokI, BsmI, ApaI, and TaqI SNPs with BA. A total of 168 subjects were screened for VDR SNPs using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. The obtained results showed statistically significant differences in the distribution of FokI genotypes (df = 2; P = 0.008) and alleles (P = 0.002; OR = 0.446; 95%CI = 0.264-0.752) between patients and controls. Distributions of BsmI, ApaI, and TaqI genotypes and alleles did not show statistical differences. BsmI, ApaI, and TaqI SNPs are in linkage disequilibrium (LD) in the whole studied group, as well as in BA patients and controls. The strongest LD was observed between BsmI and TaqI (r²  = 0.69 for all subjects in the study; r²  = 0.75 in BA; r²  = 0.64 in controls), while lower values of LD were observed for BsmI and ApaI, and ApaI and TaqI SNPs. This is the first study that examined the association of VDR SNPs (FokI, BsmI, ApaI, and TaqI) in Serbian patients with BA indicating protective effect of FF genotype and F allele of FokI SNP on BA development. J. Cell. Biochem. 118: 3986-3992, 2017. © 2017 Wiley Periodicals, Inc.

Evaluation of genetic factors involved in nocturnal electromyographic activity of masticatory muscles in twins

OBJECTIVES

The objectives of this study were to assess sleep bruxism events by directly recording electromyographic activity during sleep and to reveal the relative importance of genetic and environmental factors involved in sleep bruxism in twins.

MATERIAL AND METHODS

The subjects consisted of 108 twins (mean age 22.2 ± 6.4 years). Electromyographic activity of temporalis muscles during sleep was evaluated using a portable automatic sleep bruxism analyzer (Grindcare 3.0, Medotech A/S), and recordings were carried out for at least three consecutive nights. Quantitative genetic statistics based on structural equation modeling was utilized to estimate variance components.

RESULTS

Monozygotic twin-pair correlation for the number of nocturnal electromyographic activities recorded in this study (r = 0.463, P = 0.009) was higher than dizygotic twin-pair correlation (r = 0.103, P = 0.725). The proportion of total phenotypic variance in the liability of sleep bruxism to attribute to genetic influences, related to the electromyographic activities, was 48 % (95 % CI 17-95 %) and to unique environmental influences was 52 % (95 % CI 28-82 %).

CONCLUSIONS

Additive genetic effects may be a contributing factor to the occurrence of nocturnal EMG activity associated with sleep bruxism.

CLINICAL RELEVANCE

A greater understanding of the contribution of genetic factors could have beneficial uses, including enhanced accuracy of sleep bruxism diagnosis, management of sleep bruxism, and enhanced estimation of the prognosis for patients suffering from sleep bruxism. In addition, it could be also important to adequately evaluate the environmental factors in patients with sleep bruxism.

Association between circulating vitamin D, the Taq1 vitamin D receptor gene polymorphism and colorectal cancer risk among Jordanians

BACKGROUND

The physiological role of vitamin D extends beyond bone health and calcium-phosphate homeostasis to effects on cancer risk, mainly for colorectal cancer. Vitamin D may have an anticancer effect in colorectal cancer mediated by binding of the active form 1,25(OH)2D to the vitamin D receptor (VDR). The Taq1 VDR gene polymorphism, a C-to-T base substitution (rs731236) in exon 9 may influence its expression and function. The aim of this study was to determine the 25(OH)D vitamin D level and to investigate the association between circulating vitamin D level and Taq1VDR gene polymorphism among Jordanian colorectal cancer patients.

MATERIALS AND METHODS

This case control study enrolled ninety-three patients and one hundred and two healthy Jordanian volunteers from AL-Basheer Hospital/Amman (2012-2013). Ethical approval and signed consent forms were obtained from all participants before sample collection. 25(OH)D levels were determined by competitive immunoassay Elecsys (Roche Diagnostic, France). DNA was extracted (Promega, USA) and amplified by PCR followed by VDR Taq1 restriction enzyme digestion. The genotype distribution was evaluated by paired t-test and chi-square. Comparison between vitamin D levels among CRC and control were assessed by odds ratio with 95% confidence interval.

RESULTS

The vitamin D serum level was significantly lower among colorectal cancer patients (8.34 ng/ml) compared to the healthy control group (21.02 ng/ml). Patients deficient in vitamin D (less than 10.0 ng/ml) had increased colorectal cancer risk 19.2 fold compared to control. Only 2.2% of CRC patients had optimal vitamin D compared to 23.5% among healthy control. TT, Tt and tt Taq1 genotype frequencies among CRC cases was 35.5%, 50.5% and 14% compared to 43.1%, 41.2% and 15.7% among healthy control; respectively. CRC patients had lower mean vitamin D level among TT (8.91 ± 4.31) and Tt (9.15 ± 5.25) genotypes compared to control ((21.3 ± 8.31) and (19.3 ± 7.68); respectively.

CONCLUSIONS

There is significant association between low 25(OH)D serum level and colorectal cancer risk. The VDRTaq1 polymorphism was associated with increased colorectal cancer risk among patient with VDRTaq1 TT and Tt genotypes. Understanding the functional mechanism of VDRTaq1 TT and Tt may provide a strategy for colorectal cancer prevention and treatment.

Association of polymorphisms in the vitamin D receptor promoter with idiopathic short stature

The genetic alterations of vitamin D receptor (VDR) are related with the growth of long bone. There were a lot of reports regarding an association of polymorphisms in the VDR promoter with many disorders, but not with idiopathic short stature (ISS). We investigated the association of them with ISS. A total of 50 subjects, including 29 ISS patients and 21 healthy controls with their heights within the normal range was recruited. We selected two single nucleotide polymorphisms (SNPs) from VDR promoter (rs11568820 at the Cdx-2 binding site upstream of exon 1e and rs4516035 at -1012 upstream of exon 1a) as candidates, respectively. In genotype analysis, the frequency of A/A genotype at the Cdx-2 binding site locus (rs11568820) upstream of exon 1e of VDR was decreased to 6.9% in ISS patients (28.6% in controls) (P = 0.027). The genetic variation at the Cdx-2 binding site of VDR promoter can be a contributing factor of growth of height.

RT-qPCR assay on the vitamin D receptor gene in type 2 diabetes and hypertension patients in Turkey

RT-qPCR was used to analyze the vitamin D receptor (VDR) gene TaqI polymorphism in 100 Turkish patients with type 2 diabetes mellitus (T2DM) and hypertension compared with 100 healthy subjects, to determine whether VDR could be considered as one of the susceptibility genes for T2DM and hypertension. Genotyping was done with PCR, followed by melting curve analysis with specific fluorescent hybridization probes. The results showed that distributions for TT, Tt and tt genotypes were 51, 46 and 3% in the patient group, and 35, 49 and 16% in the control group, respectively. The frequency of the T allele in patients was also significantly higher than that in controls. Based on the results, the relationship between the VDR gene TaqI polymorphism and T2DM patients in the Turkish population was compared. In terms of the genotype distributions and allele frequencies of the VDR gene TaqI polymorphism, there was no statistically significant difference (P > 0.05) between the T2DM and hypertension patients and controls. Application of RT-qPCR method enabled us to assess the prevalence of the VDR gene TaqI polymorphism and its association with type 2 diabetes and hypertension.

Frequency of fokI and taqI polymorphism of vitamin D receptor gene in Indian population and its association with 25-hydroxyvitamin D levels

BACKGROUND:

The VDR protein is at the centre of the vitamin D endocrine system, a complex physiological system with substantial feedback regulatory mechanisms involved in maintaining serum calcium and 1, 25 dihydroxy vitamin D3. Variations in VDR gene are shown to have implications in several diseases and have also been implicated as an important genetic factor affecting bone mass.

AIM:

To determine the frequency of Fok I and Taq I variants in healthy Indian individuals and its association with 25-OH-Vitamin D levels.

SETTINGS AND DESIGN:

Blood samples were collected from 143 unrelated normal individuals (Male-84 and Female-59) and their genotypes determined.

MATERIALS AND METHODS:

After amplification by polymerase chain reaction, each polymorphism was genotyped by restriction fragment length polymorphism. For 100 normal healthy individuals 25-hydroxyvitamin D estimation was done using DiaSorin kit method.

STATISTICAL ANALYSIS:

Graph pad software was used to calculate the P values from the Chi-square.

RESULTS:

Out of 143 samples analyzed for FokI and TaqI polymorphisms the following genotypic frequency was obtained FF 59%, Ff 36%, ff 5% and TT 49%, Tt 43%, tt 8% respectively.

CONCLUSIONS:

Results indicate that the distribution of the polymorphic loci Fok I and Taq I vary considerably not only in different populations, but also within India. Furthermore, when the genotypes were analyzed with respect to 25-OH-Vitamin D levels, a significant association was seen for the Taq 1 SNP but not with the Fok I.

Vitamin D receptor gene polymorphism and bone mineral density in 0-6-year-old Han children

This study aims to investigate the four vitamin D receptor (VDR) gene single nucleotide polymorphisms and their possible relationship with bone mineral density (BMD) in Chinese 0-6-year-old Han children. Two hundred four 0-6-year-old Han children without metabolic bone disease were randomly recruited in Shanghai, China. The BMD of the middle tibia was measured by an ultrasonic bone density instrument. VDR genotypes were determined by polymerase chain reaction restriction fragment length polymorphism using endonuclease ApaI, BsmI, TaqI and FokI. The alleles of a, T, b and F and the genotypes of aa, TT, bb and Ff were predominant. The frequency alleles of a, T, b and F were, respectively, 70.6, 95.8, 95.3 and 57.6%. When the influences of confounders such as serum 25(OH)D, serum zinc and outdoor activities on BMD were removed, the genotypes of BsmI and FokI were found apparently to be related to BMD. The BMD of the Bb carrier was much lower than that of the bb carrier (22.00 ± 27.84 and 43.14 ± 31.98, P < 0.05). The BMD of the ff carrier was lower than that of the Ff or FF carrier (26.97 ± 34.22 and 37.95 ± 29.70 and 53.52 ± 30.35, P < 0.001), while the genotypes of ApaI and TaqI have no relation with BMD in 0-6-year-old Han children. These findings show that the Bb and ff genotypes of the VDR BsmI and FokI variants are significantly associated with a decreased BMD in Chinese Han children aged 0-6 years, while the VDR ApaI and TaqI polymorphisms are not significantly associated with it.

Presentation, heritability, and genome-wide linkage analysis of the midchildhood growth spurt in healthy children from the Fels Longitudinal Study

Growth is a complex process composed of distinct phases over the course of childhood. Although the pubertal growth spurt has received the most attention from auxologists and pediatricians, the midchildhood growth spurt has been less well studied. The midchildhood growth spurt refers to a relatively small increase in growth velocity observed in some, but not necessarily all, children in early to middle childhood. If present, the midchildhood growth spurt typically occurs sometime between the ages of 4 and 8 years, well before the onset of the far more pronounced pubertal growth spurt. In this study we used a triple logistic curve-fitting method to fit individual growth curves to serial stature data from 579 healthy participants in the Fels Longitudinal Study, 479 of whom have been genotyped for about 400 short tandem repeat (STR) markers spanning the genome. We categorized individuals according to the presence or absence of a midchildhood growth spurt and then conducted heritability and genome-wide linkage analyses on the dichotomous trait. In the total sample of 579 individuals, 336 (58%) were found to have evidence of having had a midchildhood growth spurt. There was a marked sex difference in presence of the midchildhood growth spurt, however, with 232 of the 293 males (79%) having had a midchildhood growth spurt but just 104 of the 286 females (36%) having had one. Presence of a midchildhood growth spurt was found to have a significant heritability of 0.37 +/- 0.14 (p = 0.003). Two quantitative trait loci with suggestive LOD scores were found: one at 12 cM on chromosome 17p13.2 (LOD = 2.13) between markers D17S831 and D17S938 and one at 85 cM on chromosome 12q14 (LOD = 2.06) between markers D12S83 and D12S326.

Association of vitamin D receptor polymorphisms with the outcome of allogeneic haematopoietic stem cell transplantation

Recently, vitamin D receptor (VDR) polymorphism has been identified as an additional genetic factor associated with the outcome after allogeneic haematopoietic stem cell transplantation (HSCT) from HLA-matched sibling donors. In the present study, VDR ApaI, TaqI and FokI alleles were typed using single strand conformation polymorphism in 123 Polish recipients and their sibling or alternative donors to test the associations of VDR polymorphisms with HSCT outcome. Four VDR genotypes were identified as risk factors of acute graft-versus-host disease (aGVHD). Donor ApaI AA (OR = 7.245, P = 0.009), source of HSC (OR = 7.001, P = 0.007), transplantation from an alternative donor (OR = 6.630, P = 0.007) and donor FokI FF (OR = 4.473, P = 0.025) significantly contributed to the development of grades II-IV aGVHD, while recipient ApaI aa (OR = 3.233, P = 0.069), recipient FokI FF (OR = 2.558, P = 0.077) and female to male transplants (OR = 2.955, P = 0.099) were found to be less significant factors. In addition, the presence of ApaI aa genotype in the recipient was found to be associated with increased likelihood of death (P = 0.0228). The present study contributes to the studies demonstrating a role of VDR polymorphisms in HSCT outcome. In addition to previously described correlations of ApaI a allele and occurrence of severe grades III-IV aGVHD and (linked with ApaI aa) recipient TaqI TT genotype with aGVHD, the novel associations of recipient and donor FokI FF genotype and the increased aGVHD risk and recipient ApaI aa with survival were identified.

Evidence for involvement of the vitamin D receptor gene in idiopathic short stature via a genome-wide linkage study and subsequent association studies

Stature is a highly heritable trait under both polygenic and major gene control. We aimed to identify genetic regions linked to idiopathic short stature (ISS) in childhood, through a whole genome scan in 92 families each with two affected children with ISS, including constitutional delay of growth and puberty and familial short stature. Linkage analysis was performed for ISS, height and bone age retardation. Chromosome 12q11 showed significant evidence of linkage to ISS and height (maximum non-parametric multipoint LOD scores 3.18 and 2.31 at 55-58 cM, between D12S1301 and D12S1048), especially in sister-sister pairs (LOD score of 1.9 for ISS in 22 pairs). These traits were also linked to chromosomes 1q12 and 2q36. The region on chromosome 12q11 had previously shown significant linkage to adult stature in several genome scans and harbors the vitamin D receptor gene, which has been associated with variation in height. A single nucleotide polymorphism (SNP) (rs10735810, FokI), which leads to a functionally relevant alteration at the protein level, showed preferential transmission of the transcriptionally more active G-allele to affected children (P=0.04) and seems to be responsible for the observed linkage (P=0.05, GIST test). Bone age retardation showed moderate linkage to chromosomes 19p11-q11 and 7p14 (LOD scores 1.69 at 57 cM and 1.42 at 50 cM), but there was no clear overlap with linkage regions for stature. In conclusion, we identified significant linkage, which might be due to a functional SNP in the vitamin D receptor (VDR) gene and could be responsible for up to 34% of ISS cases in the population.

Association of sequence variations in the gene encoding adiponectin receptor 1 (ADIPOR1) with body size and insulin levels. The Finnish Diabetes Prevention Study

AIMS/HYPOTHESIS

Adiponectin is a circulating peptide derived from adipose tissue. It mediates its insulin-sensitising and anti-atherogenic effects on target tissues through two known receptors, adiponectin receptors 1 and 2 (ADIPOR1; ADIPOR2), which are encoded by the genes ADIPOR1 and ADIPOR2. Our aim was to study the association of ADIPOR1 gene variations with body size and risk of type 2 diabetes in subjects with impaired glucose tolerance, who participated in the Finnish Diabetes Prevention Study (DPS).

SUBJECTS AND METHODS

We selected seven single nucleotide polymorphisms (SNPs) of the ADIPOR1 gene to perform association studies with anthropometrics and metabolic parameters at baseline, and with the risk of type 2 diabetes during the 3-year follow-up in the DPS study population. Both single SNP analysis and haplotype effects were studied.

RESULTS

Three out of seven markers studied (rs10920534, rs22757538 and rs1342387) were significantly associated with various body size measurements including weight, height, waist and hip circumference, sagittal diameter and body mass index. Furthermore, three markers (rs10920534, rs12045862 and rs7539542), of which two were different from those associating with body size, were linked to fasting and 2-h insulin levels, particularly in men at baseline. The haplotype analysis with five markers revealed seven major haplotypes in the DPS study population. The haplotype effects on body size measures were in line with those of single SNP analysis. However, none of the markers were associated with the risk of type 2 diabetes.

CONCLUSIONS/INTERPRETATION

Our findings suggest that ADIPOR1 has a putative role in the development of body size, and that traits for central adiposity and insulin resistance may be dissociated from each other.

Association of estrogen receptor gene polymorphisms with susceptibility to adolescent idiopathic scoliosis

STUDY DESIGN

A case-control study is presented.

OBJECTIVE

To investigate the association of estrogen receptor gene polymorphisms with adolescent idiopathic scoliosis (AIS) risk.

SUMMARY OF BACKGROUND DATA

Previous studies have shown that genetic factors are important in the pathogenesis of idiopathic scoliosis. Only 1 publication suggested that XbaI site polymorphism was associated with curve severity of idiopathic scoliosis. However, to our knowledge, the relationship of estrogen receptor gene polymorphisms and the individual susceptibility to idiopathic scoliosis has not been studied.

METHODS

This study included 202 patients with AIS and 174 healthy controls. Height, menarche status, curve pattern, Cobb angle, and Risser sign in female patients were recorded. There were 2 polymorphic loci, PvuII and XbaI locus, of estrogen receptor analyzed by restriction fragment length polymorphisms.

RESULTS

The frequency of XX genotype was significantly higher in patients than that in controls (P = 0.005). The X allele appeared to be overrepresented in patients compared with controls (P = 0.001). Furthermore, the frequencies of XX genotype in female patients whose height was > or = 160 cm and Cobb angle > or = 40 degrees were higher than those whose height was <160 cm and Cobb angle <40 degrees (P = 0.001 and P < 0.001, respectively).

CONCLUSIONS

The XbaI site polymorphism of estrogen receptor gene may be associated with a risk of AIS.

Genetics of human growth

Genes involved in human growth consist of major growth genes and minor growth genes. Major growth genes have fundamental effects on human growth, and their mutations cause growth failure (or overgrowth) which are recognizable as single gene disorders. Minor growth genes exert relative minor additive effects on human growth, and their combination is involved in the development of short (or tall) stature as a multifactorial trait. This review summarizes the current knowledge about the major and the minor growth genes, and refers to the recent molecular approach of identification of the growth genes.

Strong association between polymorphisms in ANKH locus and skeletal size traits

Loss of bone strength is the main determinant of bone fragility. Bone strength is directly dependent on bone size (BS). A substantial portion of BS variation is attributable to genetic effects. However, the list of genes and allelic variants involved in the determination of BS variation is far from being complete. Polymorphisms in the ANKH gene have been shown to be associated with radiographic hand BS-related phenotypes. The present study examined the possible association of the ANKH gene with skeletal size and shape in order to test the universality of the ANKH effect on BS traits. Our sample consisted of a total of 212 ethnically homogeneous nuclear families (743 individuals) of European origin. Each individual was measured for body height, weight, and several other anthropometrical measurements, and genotyped for nine polymorphic markers (the average heterozygosity level was 0.4). We observed significant associations with practically all the anthropometrical phenotypes studied. More specifically, we found associations with body weight and height, limb length (P</=0.001; promoter region). After adjustment for body height, we demonstrated the substantial association increase for biacromial breadth (P=0.0012; some 140 kb downstream from ANKH) and vertebral column length (P=0.0008; exons 2-7 region). The majority of the observed associations persisted even after correction for multiple testing. For the first time the reliable evidence in support of universality of ANKH gene polymorphisms effect on bone size was provided.

Vitamin D receptor gene polymorphisms are linked to and associated with adult height

BACKGROUND

The vitamin D receptor (VDR) gene is important to human stature, as it mediates metabolic pathways, calcium homeostasis, and phosphate homeostasis, which influence growth.

METHODS

We examined the relationship between VDR and adult height in 1873 white subjects from 406 nuclear families. Four SNPs, namely -4817A/G at intron 1, FokI C/T at exon 2 start codon, BsmI A/G at intron 8, and TaqI T/C at exon 9 in VDR were tested for linkage and association with adult height variation by the program QTDT (quantitative transmission disequilibrium test). The bT haplotype of the BsmI and TaqI loci was further tested for its association with height in unrelated samples randomly chosen from the 406 nuclear families by traditional population association methods.

RESULTS

All four tested SNPs were linked to adult height. Within family associations with height were detected at BsmI and TaqI loci (p = 0.048 and 0.039, respectively). Analyses based on BsmI/TaqI haplotypes also revealed evidence for linkage (p = 0.05) and association (p = 0.001) with height. The bT haplotype was significantly associated with higher adult height (p = 0.033, within family association test). Such an association might be female specific and influenced by menstrual status.

CONCLUSIONS

Our results strongly suggest that VDR may be linked to and associated with adult height variation in white populations.

Two single-nucleotide polymorphisms in the human vitamin D receptor promoter change protein–DNA complex formation and are associated with height and vitamin D status in adolescent girls

Numerous association studies have dealt with single-nucleotide polymorphisms (SNPs) in coding and intronic regions of the human vitamin D receptor (hVDR) gene. We have hypothesized that phenotypic traits may also be associated with variations in VDR expression due to the presence of SNPs in promoter regions. In this work, we have studied two SNPs located 1521 bp (G/C) and 1012 bp (A/G) upstream of the transcriptional start site of the main human VDR gene promoter. One base-change in any of the two variant sites led to a dramatic change in protein-DNA complex formation using nuclear extracts from HEK293, Caco-2 and COS-7 cells. Genetic analysis of 185 healthy adolescent girls evidenced two major haplotypes: 1521G/1012A and 1521C/1012G and three main genotypes: homozygous for 1521G/1012A (21.1%), homozygous for 1521C/1012G (17.3%) and heterozygous 1521CG/1012GA (57.3%). On the basis of transfection data, promoter activity was nearly 2-fold higher with the 1521G/1012A haplotype, when compared with the 1521C/1012G haplotype. Clinical and biological association study in the adolescent cohort showed that girls with a CC/GG genotype had (i) lower circulating levels of 25-dihydroxyvitamin D, with no detectable consequence on calcium metabolism, (ii) lower serum IGF-1 levels and (iii) smaller height from 11 years of age up to adult height.

Genetic and environmental correlations between bone phenotypes and anthropometric indices in Chinese

Height, weight, bone mineral density (BMD), and bone size are all influenced by genetic and environmental factors as well as interactions between them. Height and weight are often used in population studies to adjust the bone phenotypes. However, it is still unknown what proportion of genetic and environmental variability is shared between these anthropometric characteristics and the bone phenotypes. The genetic and environmental correlations between the bone phenotypes and anthropometric indices in Chinese subjects were studied by bivariate quantitative genetic analysis on a sample of 931 healthy subjects from 292 Chinese nuclear families aged from 19 to 79 years. BMD and bone size at the lumbar spine (L1-L4) and the hip of all subjects were measured by dual-energy X-ray absorptiometry. We found significant genetic correlations between weight and spine BMD, hip BMD, spine bone size and hip bone size, which were 0.50 (P<0.01), 0.45 (P<0.01), 0.36 (P=0.02), and 0.38 (P<0.01), respectively. Likewise, significant genetic correlations between height and spine BMD, spine bone size, and hip bone size were 0.30 (P=0.02), 0.54 (P<0.01), and 0.58 (P<0.01), respectively. The environmental correlations were found to be significant only between height and spine bone size (P<0.001) and weight and hip BMD (P=0.02). These results suggest the probability that the same genetic and environmental factors contribute to these different phenotypes. Moreover, when a candidate gene or genomic region is responsible for the variation of both bone phenotypes and anthropometric indices, its true genetic effect on the bone phenotypes may be lost after one has adjusted the phenotypic values with weight and height as random environmental factors. It may have implications for population studies of candidate genes that underlie the complex bone phenotypes and for the development of strategies for therapeutic application.

QTLs for height: results of a full genome scan in Dutch sibling pairs

Height is a highly heritable, complex trait. At present, the genes responsible for the variation in height have not yet been identified. This paper summarizes the results of previous linkage studies and presents results of an additional linkage analysis. Using data from the Netherlands Twin Register, a sib-pair-based linkage analysis for adult height was conducted. For 513 sib-pairs from 174 families complete genome scans and adult height were available. The strongest evidence for linkage was found for a region on chromosome 6, near markers D6S1053 and D6S1031 (LOD = 2.32). This replicated previous findings in other data sets. LOD scores ranging from 1.53 to 2.04 were found for regions on chromosomes 1, 5, 8, 10, and 18. The region on chromosome 18 (LOD = 1.83) also corresponded with the results of previous studies. Several chromosomal regions are now implied in the variance in height, but further study is needed to draw definite conclusions with regard to the significance of these regions for adult height.

[Association of vitamin D receptor gene polymorphism with type 1 diabetes mellitus in two Spanish populations]

BACKGROUND AND OBJECTIVE

In order to assess whether vitamin D receptor gene polymorphisms are involved in the genetic regulation of type 1 diabetes susceptibility, a case-control study was conducted in two Spanish populations with different genetic backgrounds.

PATIENTS AND METHOD

155 patients with childhood-onset type 1 diabetes and 280 healthy controls from Barcelona, and 89 patients and 116 controls from Navarre were studied for vitamin D receptor gene polymorphisms in peripheral blood DNA. Intron 8 (BsmI) and exon 2 (FokI) segments were amplified by PCR and sequenced to determine each corresponding genotype. Differences for allele, genotype and combined haplotype and genotype distribution between patients and controls within each population and between the two populations were analyzed.

RESULTS

BsmI genotype and allele frequencies showed a tendency towards increased bb genotype and b allele frequencies in Barcelona patients and the tendency was inverse in Navarre. FokI polymorphism distribution analysis showed a significant decrease in ff genotype (p = 0.016) in patients versus controls from Navarre. Combined genotypes showed homozygous bb/FF genotype to be increased in Barcelona patients (p = 0.04) whereas homozygous bb/ff genotype was decreased in Navarre patients (p = 0.02) versus their corresponding controls. BF haplotype frequency distribution between patients and controls was inverse and significantly different between Barcelona and Navarre (p = 0.04).

CONCLUSIONS

Combined genotypes for vitamin D receptor gene polymorphisms at intron 8 and exon 2 suggest that the more active form of vitamin D receptor gene (FF genotype) can be increased in Mediterranean diabetic patients whereas the less active form (ff genotype) can be decreased in those from Navarre. Our results suggest that, in both groups, the F allele of exon 2 VDR gene polymorphism may increase type 1 diabetes susceptibility.

Nutrition influences bone development from infancy through toddler years

During the last decade a greater appreciation has developed for determining factors that influence bone accretion in healthy children. Nutritional factors that may contribute to bone accretion in infants and toddlers include maternal nutritional status during pregnancy, type of infant feeding, calcium and phosphorus content of infant formula, introduction of weaning foods, and diet during the toddler and preschool years. Maternal vitamin D deficiency during pregnancy is associated with disturbances in neonatal calcium homeostasis, and maternal calcium deficiency leads to reduced neonatal bone mineral content (BMC). Preterm infants are at increased risk of osteopenia, and, although the use of high mineral formula has reduced the risk of osteopenia in these infants, it has not eliminated it. The reason for the long-term bone deficiency among preterm infants is not clear, although lower physical activity levels have been suggested as a potential cause. Studies find that human milk-fed infants have lower bone accretion than do formula-fed infants; that the greater the mineral content of formula, the greater the bone accretion; and that the inclusion of palm olein oil in infant formula may reduce bone mineral accretion. Bone accretion is not influenced by the timing of the introduction of weaning foods, despite higher serum parathyroid hormone (PTH) concentrations among infants who receive solids earlier. There is evidence of calcium intake-by-gene and calcium intake-by-physical activity interactions among toddlers and young children. The long-term effects of these early nutritional influences on later bone health are unknown.

Analysis of polymorphisms of the vitamin D receptor, estrogen receptor, and collagen Ialpha1 genes and their relationship with height in children with bone cancer

PURPOSE

The authors' objectives were to compare height at diagnosis of children with bone tumors with that of Spanish reference children; to analyze the frequency of the genotypes for the polymorphisms of the vitamin D receptor (VDR), estrogen receptor (ER), and collagen Ialpha1 (COLIalpha1) genes in patients and in healthy controls; and to test the relationship between the genetic markers and height.

PATIENTS AND METHODS

Height and weight at diagnosis were measured in 58 osteosarcoma and 36 Ewing sarcoma patients and compared with standards published for Spanish reference children according to sex and age. For the molecular analysis, genetic polymorphisms of the VDR (Fok I, Apa I, and TaqI), ER (Pvu II and XbaI), and COLIalpha1 (Msc I) genes were characterized in 72 osteosarcoma and 53 Ewing sarcomas and in a group of 143 healthy matched children.

RESULTS

Osteosarcoma and Ewing sarcoma patients were significantly taller than Spanish reference children. Osteosarcoma patients showed a significantly higher frequency of the Ff genotype for the Fok I polymorphism (VDR gene) than the control group. The odds ratio for this genotype was 1.78, with an increased relative risk of 78% for heterozygous Ff carriers. Among Ewing sarcoma patients, this same genotype was significantly associated with lower height than homozygotes (FF or ff).

CONCLUSIONS

Children with bone cancer are significantly taller than the reference population, which may be influenced by the genotype for the Fok I polymorphism of the VDR gene.

A whole-genome linkage scan suggests several genomic regions potentially containing QTLs underlying the variation of stature

Human height is a complex trait under the control of both genetic and environment factors. In order to identify genomic regions underlying the variation of stature, we performed a whole-genome linkage analysis on a sample of 53 human pedigrees containing 1,249 sib pairs, 1,098 grandparent-grandchildren pairs, 1,993 avuncular pairs, and 1,172 first-cousin pairs. Several genomic regions were suggested by our study to be linked with human height variation. These regions include 5q31 at 144 cM from pter on chromosome 5 (with a maximum LOD score of 2.14 in multipoint linkage analyses), Xp22 at the marker DXS1060, and Xq25 at DXS1001 on the X chromosome (with LOD scores of 1.95 and 1.91, respectively, in two-point linkage analyses). Noticeably, Xp22 happens to be the very region where a newly identified gene underlying idiopathic short stature, SHOX, maps. Based on our findings, further confirmation and fine-mapping studies are to be pursued on expanded samples and/or with denser markers for eventual identification of major functional genes involved in human height variation.

Association between estrogen receptor gene polymorphisms and curve severity of idiopathic scoliosis

STUDY DESIGN

Analysis of the estrogen receptor gene of girls with idiopathic scoliosis.

OBJECTIVES

To determine whether estrogen receptor gene polymorphisms correlate with curve severity of adolescent idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Studies suggest that idiopathic scoliosis is a familial condition and that curve progression is related to genetically determined factors, such as skeletal and sexual growth.

METHODS

A total of 304 girls with idiopathic scoliosis were followed until growth maturation. Height, arm span, menarcheal age, and age at growth maturation were recorded, and curve severity was measured using Cobb's method. The estrogen receptor gene, which contains polymorphic PvuII and XbaI sites, was amplified from lymphocyte deoxyribonucleic acid by polymerase chain reaction.

RESULTS

The mean maximum Cobb measurements for patients with genotypes XX and Xx were greater than for those with genotype xx (P = 0.002). The risk of curve progression, defined as progression of >5 degrees from initial evaluation, was higher with genotype Xx than with xx (P = 0.03). Patients with genotypes XX and Xx had a significantly higher risk for operative treatment than those with genotype xx (21.4%, 24.7% vs. 7.6%, P< 0.001). Growth examination around the time of the growth spurt revealed that the XbaI site polymorphism was also related to the age of growth maturation. The frequency of patients with growth maturation at >or=16 years was higher for genotypes XX and Xx than for genotype xx (33.3%, 29.9% vs. 16.8%, P= 0.013).

CONCLUSION

Our results suggest that the XbaI site polymorphism is associated with curve severity. DNA analysis may predict curve progression.

Vitamin D receptor gene polymorphism associates with graft-versus-host disease and survival in HLA-matched sibling allogeneic bone marrow transplantation

We investigated the role of polymorphism of the vitamin D receptor (VDR) gene in HLA-matched sibling BMT for polymorphisms previously associated with human disease pathology. In intron 8 of the VDR gene, the B and A alleles of the BsmI and ApaI RFLPs were found to associate with reduced aGVHD when present in the patient's genotype. Logistic regression analysis demonstrated that patient VDR genotype, along with previously identified IL-10(-1064) and IFN-gamma genotype to be risk factors for severe acute GVHD. The A allele also associates with increased likelihood of death when present in the donor genotype (AA vs Aa or aa, hazard ratio 2.03, P = 0.0232). In patients who received increased prophylaxis with multi-agent therapy, patients whose graft was from a donor with an AA genotype had a substantially worse survival than patients whose graft was from a donor with a non-AA genotype (hazard ratio 12.93, P < 0.0001). Analysis of VDR genotype in prospective BMT recipients could indicate patients at risk of severe aGVHD. Analysis of VDR genotype in prospective BMT donors may identify individuals who have greater transplant-related mortality, and also allow appropriately restricted use of increased immunosuppressive prophylaxis.

Effect of VDR polymorphisms on growth and bone mineral density in homozygous beta thalassaemia

We examined the effect of vitamin D receptor (VDR) polymorphisms at exon 2 (FokI) and intron 8 (BsmI) on the stature and bone mineral density at femoral neck (FBMD) and lumbar spine (LBMD) in 108 prepubertal and pubertal homozygous beta thalassaemic patients, regularly treated. We found significantly shorter stature and lower LBMD and FBMD in all patients with CC VDR genotype, and significant shorter height and lower LBMD in prepubertal and pubertal female patients with BB VDR genotype. Because homozygous CC and BB VDR genotypes influence Vitamin D activity, they can be considered additional risk factors for bone disease in beta thalassaemia.

Genomewide linkage analysis of stature in multiple populations reveals several regions with evidence of linkage to adult height

Genomewide linkage analysis has been extremely successful at identification of the genetic variation underlying single-gene disorders. However, linkage analysis has been less successful for common human diseases and other complex traits in which multiple genetic and environmental factors interact to influence disease risk. We hypothesized that a highly heritable complex trait, in which the contribution of environmental factors was relatively limited, might be more amenable to linkage analysis. We therefore chose to study stature (adult height), for which heritability is approximately 75%-90% (Phillips and Matheny 1990; Carmichael and McGue 1995; Preece 1996; Silventoinen et al. 2000). We reanalyzed genomewide scans from four populations for which genotype and height data were available, using a variance-components method implemented in GENEHUNTER 2.0 (Pratt et al. 2000). The populations consisted of 408 individuals in 58 families from the Botnia region of Finland, 753 individuals in 183 families from other parts of Finland, 746 individuals in 179 families from Southern Sweden, and 420 individuals in 63 families from the Saguenay-Lac-St.-Jean region of Quebec. Four regions showed evidence of linkage to stature: 6q24-25, multipoint LOD score 3.85 at marker D6S1007 in Botnia (genomewide P<.06), 7q31.3-36 (LOD 3.40 at marker D7S2195 in Sweden, P<.02), 12p11.2-q14 (LOD 3.35 at markers D12S10990-D12S398 in Finland, P<.05) and 13q32-33 (LOD 3.56 at markers D13S779-D13S797 in Finland, P<.05). In a companion article (Perola et al. 2001 [in this issue]), strong supporting evidence is obtained for linkage to the region on chromosome 7. These studies suggest that highly heritable complex traits such as stature may be genetically tractable and provide insight into the genetic architecture of complex traits.

Vitamin D receptor gene polymorphism is associated with birth height, growth to adolescence, and adult stature in healthy caucasian men: a cross-sectional and longitudinal study

Vitamin D receptor (VDR) polymorphism has been associated with bone mineral density (BMD), but recent data indicate association to parameters of body constitution and growth. We investigated VDR gene polymorphism, defined by BsmI and TaqI, in 90 healthy Caucasian males and any relation with parameters of body constitution at birth, and to parameters of body constitution, BMD and bone area, at age 16.9 +/- 0.3 yr (mean +/- SD) and at age 19.2 +/- 0.7. Using PCR and the restriction enzyme BsmI and TaqI, the allelic variants BB, Bb, and bb, and TT, Tt, and tt were identified. Height (cm) and weight (kg) were measured using standardized equipment, and BMD of the total body, lumbar spine, and femoral neck, and bone area (cm2) of the total body, humerus, femur was measured using dual-energy x-ray absorptiometry. BsmI and TaqI genotypes were related in 89 of the 90 cases; hence, the same associations were found for both genotypes. Boys with the BB genotype were shorter at birth (P = 0.01) and grew less from birth to age 16.9 +/- 0.3 (P = 0.01) than their Bb and bb counterparts. Both during puberty (age 16.9 +/- 0.3) and after puberty (age 19.3 +/- 0.7), the BB boys were shorter (P = 0.005-0.008) and had lower bone area of the humerus, femur, and total body (P < 0.05) than the Bb and bb boys. The allelic variants were not related to BMD at any site. A prediction model including parental height, birth height, birth weight, and VDR alleles could predict up to 39% of the total variation in adult height in our population. The VDR allelic variants alone contributed to 8% of the total variation.