Biallelic frameshift variants in PHLDB1 cause mild-type osteogenesis imperfecta with regressive spondylometaphyseal changes.

BACKGROUND: Osteogenesis imperfecta (OI) is a heterogeneous group of inherited disorders characterised by susceptibility to fractures, primarily due to defects in type 1 collagen. The aim of this study is to present a novel OI phenotype and its causative candidate gene. METHODS: Whole-exome sequencing and clinical evaluation were performed in five patients from two unrelated families. PHLDB1 mRNA expression in blood and fibroblasts was investigated by real-time PCR, and western blot analysis was further performed on skin fibroblasts. RESULTS: The common findings among the five affected children were recurrent fractures and/or osteopaenia, platyspondyly, short and bowed long bones, and widened metaphyses. Metaphyseal and vertebral changes regressed after early childhood, and no fractures occurred under bisphosphonate treatment. We identified biallelic NM_001144758.3:c.2392dup and NM_001144758.3:c.2690_2693del pathogenic variants in PHLDB1 in the affected patients, respectively, in the families; parents were heterozygous for these variants. PHLDB1 encodes pleckstrin homology-like domain family B member-1 (PHLDB1) protein, which has a role in insulin-dependent Akt phosphorylation. Compared with controls, a decrease in the expression levels of PHLDB1 in the blood and skin fibroblast samples was detected. Western blot analysis of cultured fibroblasts further confirmed the loss of PHLDB1. CONCLUSION: Two biallelic frameshift variants in the candidate gene PHLDB1 were identified in independent families with a novel, mild-type, autosomal recessive OI. The demonstration of decreased PHLDB1 mRNA expression levels in blood and fibroblast samples supports the hypothesis that PHLDB1 pathogenic variants are causative for the observed phenotype.

Association of Intelectin 1 Gene rs2274907 A > T Polymorphism with Obesity, Type 2 Diabetes, Serum Intelectin-1 Levels and Lipid Profiles in Turkish Adults.

The anti-inflammatory adipokine intelectin-1, which is encoded by the ITLN1 gene, is hypothesized to be linked to the pathogenesis of type 2 diabetes (T2DM) and obesity. The purpose of this study was to examine the effect of the ITLN1 gene polymorphism rs2274907 on obesity and T2DM in Turkish adults. The impact of genotype on lipid profiles and serum intelectin levels in the obese and diabetes groups was also investigated. Randomly selected 2266 adults (mean age, 55.0 ± 11.7 years; 51.2% women) participating in the population-based Turkish adult risk factor study were cross-sectionally analyzed. The genotyping of rs2274907 A > T polymorphism was performed by using the hybridization probe based LightSNiP assay in real-time PCR. T2DM were defined using the criteria of the American Diabetes Association. Obesity was described as Body mass index ≥ 30 kg/m2. Statistical analyses were used to investigate the association of genotypes with clinical and biochemical measurements. According to findings, there was no vital connection between the rs2274907 polymorphism and obesity, T2DM, or serum intelectin-1 level. The TA+AA carriers had significantly higher triglyceride levels (p = 0.007) compared with the TT carriers in both obese and T2DM women when adjusted for relevant covariates. ITLN1 rs2274907 polymorphism is not correlated with the risk of obesity and T2DM and not affect serum ITLN1 levels in Turkish adults. However, this polymorphism appears to be important in regulating triglyceride levels in obese and diabetic women.

Neurofibromatosis type 1: Expanded variant spectrum with multiplex ligation-dependent probe amplification and genotype-phenotype correlation in 138 Turkish patients.

OBJECTIVE: To investigate the variant spectrum and genotype-phenotype correlations in a Turkish cohort with Neurofibromatosis Type-1 (NF1). MATERIALS AND METHODS: We retrospectively investigated the clinical and molecular data of 138 NF1 patients from 129 families who had been followed-up for a median of 3.9 (1.25-18.5) years. RESULTS: NF1 sequencing revealed 73 different intragenic variants, 19 of which were novel. Seven large deletions were detected by multiplex ligation-dependent probe amplification (MLPA) analyses. The total detection rate of pathogenic NF1 variants was found to be 87.1%. Comparing age groups, cutaneous neurofibromas, freckling, and Lisch nodules were more prevalent in patients older than 12 years (p > .05). Optic glioma detected in 17.3% of the patients and was significantly more common before the age of 6 (p > .001). Other solid tumors developed in 5% of the patients. There was no genotype-phenotype correlation between patients with truncating and nontruncating variants. However, six out of seven patients with large deletions had significant developmental delay, one patient with the c.2970_2972delAAT (p.Met992del) variant had only typical pigmentary features, and another patient with the c.4267A > G (p.Lys1423Glu) variant had CALMs, freckling, neurofibromas, and Noonan-like phenotype. CONCLUSIONS: We described 19 novel variants and seven large deletions in NF1. Applying MLPA assay in NF1 is useful in expanding the molecular diagnosis. Although very limited genotype-phenotype correlation has been reported in NF1, the fact that specific phenotypic findings were observed in our patients with large deletions and two intragenic variants supports the studies published recently.

Investigation of (epi)genotype causes and follow-up manifestations in the patients with classical and atypical phenotype of Beckwith-Wiedemann spectrum.

Beckwith-Wiedemann syndrome (BWS) is a genomic imprinting disorder, characterized by macroglossia, abdominal wall defects, lateralized overgrowth, and predisposition to embryonal tumors. It is caused by the defect of imprinted genes on chromosome 11p15.5, regulated by imprinting control (IC) domains, IC1, and IC2. Rarely, CDKN1C and chromosomal changes can be detected. The aim of this study is to retrospectively evaluate 55 patients with BWS using the new diagnostic criteria developed by the BWS consensus, and to investigate (epi)genetic changes and follow-up findings in classic and atypical phenotypes. Loss of methylation in IC2 region (IC2-LoM), 11p15.5 paternal uniparental disomy (pUPD11), and methylation gain in IC1 region (IC1-GoM) are detected in 31, eight, and five patients, respectively. Eleven patients have had no molecular defects. Thirty-five patients are classified as classical and 20 as atypical phenotype. Patients with classical phenotype are more frequent in the IC2-LoM (25/31), while patients with atypical phenotype are common in the pUPD11 group (5/8). Malignant tumors have developed in six patients (10.9%); three of these patients have IC1-GoM, two pUPD11, one IC2-LoM genotype, and four an atypical phenotype. We observed that the face was round in the infantile period and elongated as the child grew-up, developing prognathism and becoming asymmetrical if hemi-macroglossia was present in the classical phenotype. These findings were mild in the atypical phenotype. These results support the importance of using the new diagnostic criteria to facilitate the diagnosis of patients with atypical phenotype who have higher tumors risk. This study also provides important information about facial gestalt.

Levels of miR-130b-5p in peripheral blood are associated with severity of coronary artery disease.

BACKGROUND: Although patients with coronary artery disease (CAD) have a high mortality rate, the pathogenesis of CAD is still poorly understood. During the past decade, microRNAs (miRNAs) have emerged as new, potential diagnostic biomarkers in several diseases, including CAD. This study aimed to investigate the expression profiles of miRNAs in individuals with CAD and non-CAD. METHODS AND RESULTS: The Agilent's microarray analyses were performed to compare the whole blood miRNA profile of selected individuals with severe CAD (n = 12, ≥ 90% stenosis) and non-CAD (n = 12, ≤ 20 stenosis). Expressions of selected differentially expressed miRNAs (DEMs) were analyzed for validation in individuals with critical CAD (n = 50) and non-CAD (n = 43) using real-time PCR. Target prediction tools were utilized to identify miRNA target genes. We identified 6 DEMs that were downregulated in CAD patients, which included hsa-miR-18a-3p and hsa-miR-130b-5p, that were analyzed for further testing. Expression levels of hsa-miR-130b-5p were found negatively correlated with SYNTAX score and stenosis in female CAD patients (p < 0.05). In addition, both miRNAs were found positively correlated with plasma HDL and inversely correlated with fasting triglyceride levels (p < 0.05). In linear regression analysis adjusted for several confounders, the correlations have remained statistically significant. Computational prediction of target genes indicated a relevant role of hsa-miR-130b-5p and hsa-miR-18a-3p in modulating the expression of genes associated with cardiovascular diseases. CONCLUSION: Our findings highlight a significantly different pattern of miRNA expression in CAD patients in microarray results. Hsa-miR-18a-3p and hsa-miR-130b-5p might serve as biomarkers of CAD development and progression and warrant further attention.

The rs2175898 Polymorphism in the ESR1 Gene has a Significant Sex-Specific Effect on Obesity.

Polymorphisms in the ESR1 gene have been associated with obesity and lipid metabolism. There are also important sex-related differences in the prevalence of obesity and related phenotypes. Therefore, we aimed to interrogate the association of the ESR1 rs2175898 gene polymorphism with obesity, obesity-related variables, and lipid levels in men and women as separate groups. Two thousand twenty-two randomly selected middle-aged and elderly Turks were genotyped for ESR1 rs2175898 polymorphism using real-time polymerase chain reaction with hybridization probes. We found sex-related differences of the ESR1 rs2175898 polymorphism in obesity. Logistic regression analysis after adjustment for age, smoking status, physical activity, diabetes mellitus, and the presence of menopause status in women demonstrated significantly decreased risk for obesity in female AG genotype carriers (OR 0.69; 95% CI 0.52-0.91; p = 0.010), and in male GG genotype carriers (OR 0.49; 95% CI 0.25-0.96; p = 0.039), Furthermore, carriers of the rs2175898 G allele exhibited a lower body mass index in both sexes and decreased waist circumference in women but not in men. Our findings also showed significantly higher serum total-C levels (p = 0.007) in the carriers of the AG+GG/AG genotype compared with the AA genotype in men. The AG genotype of the ESR1 rs2175898 polymorphism in women and GG genotype in men were found to have a decreased likelihood for obesity compared with the other rs2175898 genotypes.

Risk of obesity and metabolic syndrome associated with FTO gene variants discloses clinically relevant gender difference among Turks.

Gene variations in the fat mass- and obesity-associated gene (FTO) have shown controversial associations with obesity and metabolic syndrome (MetS) in several populations. We explored the association of FTO gene with obesity, MetS, and insulin-related parameters separately in men and women. Two SNPs in the FTO, gene rs9939609 and rs1421085, were genotyped by the Taqman System in 1967 adults (mean age of the whole group 50.1 ± 12.0; 48.4 % male). A random sample of the Turkish Adult Risk Factor cohort was cross-sectionally analyzed. Both SNPs exhibited strong linkage disequilibrium (r(2) = 0.85) and minor alleles were associated with risk of obesity in women and of MetS in men. Carriers of the rs1421085 C-allele exhibited higher body mass index (BMI) in each gender. Adjusted fasting insulin and HOMA index were significantly higher in C-allele carriers in men alone. Logistic regression analysis demonstrated significantly increased likelihood for obesity in female C-risk allele carriers (OR 1.61; 95 % CI 1.19-2.18), after adjustment for age, smoking status, alcohol usage, physical activity grade and presence of diabetes mellitus. Male C-allele carriers were at increased risk for MetS (OR 1.44; 95 % CI 1.07-1.95), adjusted for age, smoking status, alcohol consumption, and physical activity. Further adjustment for BMI attenuated the MetS risk, indicating interaction between C-allele, gender and BMI. The FTO gene in Turkish adults contributes independently to obesity in women and-by interacting with BMI-to MetS and insulin resistance in men.

Prevalence of Prader-Willi syndrome among infants with hypotonia.

OBJECTIVE: To investigate the prevalence of Prader-Willi syndrome (PWS) in infants with hypotonia between the ages of 0 and 2 years. STUDY DESIGN: Karyotyping studies were performed in all infants with hypotonia. The study group was composed of infants with hypotonia for whom the karyotyping was found to be normal. Fluorescence in situ hybridization and methylation analysis were performed simultaneously in the study group. Molecular studies for uniparental disomy were undertaken in the patients without deletions with an abnormal methylation pattern. RESULTS: Sixty-five infants with hypotonia with a mean age of 8 months were enrolled. A deletion was detected in 6 patients by fluorescence in situ hybridization analysis. Only 1 patient had no deletion but had an abnormal methylation pattern. A maternal uniparental disomy was observed in this patient. PWS was diagnosed in 10.7 % (7/65) of the infants with hypotonia. CONCLUSION: The prevalence of PWS syndrome is high among infants with hypotonia. PWS should be considered by pediatricians and neonatologists in the differential diagnosis of all newborns with hypotonia. Early diagnosis of PWS is important for the management of these patients.

Negative results in screening for possible new sequence variations on ATP-binding cassette transporter A1 gene in Turkish adults with metabolic syndrome.

OBJECTIVES: ATP binding cassette transporter A1 (ABCA1) plays a pivotal role in the reverse cholesterol transport. Some mutations in the ABCA1 gene have correlation with changes in serum high-density lipoprotein-cholesterol (HDL-C) and other lipids concentrations. The role of genetic factors in susceptibility to metabolic syndrome (MetS) is not clear. The aim of this study was to explore the relationship between ABCA1 gene and the MetS. STUDY DESIGN: Therefore, to investigate probable new mutations in the functional regions of the ABCA1 gene, 14th, 19th and 49th exons were analyzed using single strand conformational polymorphism method in 220 subjects, 110 of whom had MetS, selected from the Turkish Adults Risk Factor study. RESULTS: No significant relationship was found between the functional region of ABCA1 and MetS. The risk for low HDL-C-high triglyceride levels and MetS are not associated with selected functional regions of the gene, 14th, 19th and 49th exons, which code for the first extracellular loop, the nucleotide binding domain and the C-terminal region, respectively. CONCLUSION: These data indicate that the mutations and polymorphisms in ABCA1 gene are not associated with MetS in Turks.

Examining the effects of coronary artery disease- and mitochondrial biogenesis-related genes' and microRNAs' expression levels on metabolic disorders in epicardial adipose tissue.

BACKGROUND AND AIMS: Epicardial adipose tissue (EAT) surrounds the heart and coronary arteries and is important for comprehending the pathogenesis of coronary artery disease (CAD). We aimed to evaluate the expressions of mitochondrial biogenesis- and CAD-related genes and miRNAs in EAT by comparing them to visceral adipose tissue (VAT) in CAD, diabetes, and obesity subgroups. METHODS: In this study, a total of 93 individuals were recruited, and EAT samples (63 CAD; 30 non-CAD) and VAT samples from 65 individuals (46 CAD; 19 non-CAD) were collected. For further analysis, the study population was divided according to obesity and diabetes status. PRKAA1, PPARGC1A, SIRT1, RELA, TNFA, and miR-155-5p, let-7g-5p, miR-1247-5p, miR-326 expression levels were examined. RESULTS: PRKAA1 and let-7g-5p were differentially expressed in EAT compared to VAT. TNFA expression was upregulated significantly in both tissues of CAD patients. In EAT, PRKAA1, PPARGC1A, and SIRT1 were downregulated with diabetes. Moreover, PPARGC1A expression is decreased under the condition of obesity in both tissues. EAT expressions of miR-1247-5p and miR-326 were downregulated with obesity, while miR-155-5p is decreased only in the VAT of obese. Also, miRNAs and genes were correlated with biochemical parameters and each other in EAT and VAT (p < 0.050). CONCLUSIONS: The findings demonstrating distinct let-7g-5p and AMPKα1 mRNA expression between EAT and VAT underscores the importance of tissue-specific regulation in different clinical outcomes. In addition, the differential expressions of investigated genes and miRNAs highlight their responsiveness to obesity, DM, and CAD in adipose tissues.

Investigation of (Epi)genetic causes in syndromic short children born small for gestational age.

Intrauterine onset syndromic short stature constitutes a group of diseases that pose challenges in differential diagnosis due to their rarity and clinical as well as molecular heterogeneity. The aim of this study was to investigate the presence of (epi)genetic causes in children born small for gestational age (SGA) and manifesting clinically undiagnosed syndromic short stature. The study group comprised twenty-nine cases selected from the syndromic SGA cohort. Various analyses were performed, including chromosomal microarray (CMA), methylation-specific-multiple ligation probe amplification for chromosomes 6,14 and 20, and whole exome sequencing (WES). Pathogenic copy number variants (CNVs) on chromosomes 2q13, 22q11.3, Xp22.33, 17q21.31, 19p13.13 and 4p16.31 causing syndromic growth disturbance were detected in six patients. Maternal uniparental disomy 14 was identified in a patient. WES was performed in the remaining 22 patients, revealing pathogenic variants in nine cases; six were monoallelic (ACAN, ARID2, NIPBL, PIK3R1, SMAD4, BRIP1), two were biallelic (BRCA2, RFWD3) and one was hemizygous (HUWE1). Seven of these were novel. Craniofacial dysmorphism, which is an important clue for the diagnosis of syndromes, was very mild in all patients. This study unveiled, for the first time, that ARID2 mutatios can cause syndromic SGA. In conclusion, a high (55.2%) diagnosis rate was achieved through the utilization of CMA, epigenetic and WES analyzes; 15 rare syndromes were defined, who were born with SGA and had atypical and/or mild dysmorphic findings. This study not only drew attention to the association of some rare syndromes with SGA, but also introduced novel genes and CNVs as potential contributors to syndromic SGA.

Minor allele of the APOA4 gene T347S polymorphism predisposes to obesity in postmenopausal Turkish women.

The aim of this study was to examine the relationship between APOA4 gene T347S polymorphism with obesity measures and serum lipids in Turkish adults. Randomly selected sample of 1,554 adults (754 men, mean age 50.4 ± 11.9 years and 800 women, mean age 49.6 ± 11.8 years) were included in the study. 346 Women (43.2 %) were postmenopausal. Genotyping was performed by using hybridization probes in real-time PCR. Not men but postmenopausal women, carrying the S347 allele, were associated with 1.5 kg/m(2) higher BMI (P = 0.016) and 3.6 cm wider waist circumference (P = 0.005) than postmenopausal T347 homozygotes, controlled for covariates. Logistic regression analyses of this polymorphism, adjusted for age, fasting triglyceride, smoking status, alcohol consumption and physical activity disclosed the rare allele to be associated with obesity in postmenopausal women at an odds of 1.80 (95 % CI 1.09-2.97; P = 0.021). Serum apoB level was lower in S347 allele carriers (110.9 ± 2.9 mg/dL) than in T347 homozygotes (119.0 ± 2.4 mg/dL; P = 0.035) in men but not women. APOA4 T347S polymorphism was unrelated to lipids and other lipoproteins in either gender. The APOA4 S347 allele predisposes to obesity and high waist circumference in Turkish postmenopausal women. ApoB levels are lower only in men in S347 allele carriers.

The Methylation Status in the Chromosome 11p15.5 Region and Metabolic Disorders in Children with Syndromic and Nonsyndromic Intrauterine Growth Restriction.

Loss of methylation (LoM) of the imprinting control region 1 (ICR1) in the chromosome 11p15.5 domain is detected in patients with Silver-Russell syndrome (SRS), characterized by asymmetric pre- and postnatal growth restriction, and typical craniofacial features. The patients with intrauterine growth restriction (IUGR) possess a high risk for adult metabolic problems. This study is aimed to investigate the methylation levels of the chromosome 11p15.5 region and metabolic problems in children with syndromic and nonsyndromic IUGR. Methylation analysis was performed for chromosome 11p15.5 in 49 patients (33 with suspected SRS and 16 nonsyndromic IUGR) with Netchine-Harbison clinical scoring (NHCS); uniparental disomy for chromosomes 6, 7, 14, and 20 was evaluated for those who were negative. LoM of ICR1 was detected in 14 of 33 suspected SRS patients with 3 or more criteria of NHCS, 5 had borderline LoM. Maternal uniparental disomy of the chromosomes 7 and 14 was found in 2 patients. The overall detection rate of SRS was 45.5%. While clinical findings were similar in patients with LoM and borderline LoM of ICR1, typical craniofacial findings were significantly less in the patients with normal methylation. Methylation patterns were not found to be impaired in the nonsyndromic IUGR group. Metabolic complications were evaluated in a total of 63 patients including 33 SRS-suspicious, 16 nonsyndromic IUGR, and 14 patients with 3M or SHORT syndrome. Increased rates of hypercalciuria, insulin resistance, and dyslipidemia were detected in patients with both syndromic and nonsyndromic IUGR. We would like to emphasize that detecting typical facial findings is effective in the diagnosis of SRS and paying attention to metabolic problems in the follow-up of patients with IUGR is recommended.

Val109Asp polymorphism in Intelectin 1 gene is associated with coronary artery disease severity in women.

OBJECTIVE: Intelectin-1 is an anti-inflammatory adipokine encoded by the Intelectin 1 (ITLN1) gene. Genetic variations in the ITLN1 gene affect the risk of coronary artery disease (CAD) and related CAD risk factors. In this study, we aimed to investigate whether the ITLN1 gene Val109Asp polymorphism has an effect on the severity of CAD and serum lipid levels in both men and women. METHODS: A total of 493 subjects who underwent coronary angiography (43.5% women, mean age 63.1±9.5 years) were grouped as individuals with critical CAD (≥70% stenosis, n=202), non-critical CAD (31%-69% stenosis, n=90), and non-CAD (control group) (1%-30% stenosis, n=201). Genotyping was performed using LightSNiP assay in Real-Time PCR. RESULTS: The frequency of the Val allele was significantly different among all the patients with critical CAD (n=41) and non-CAD control (n=51) groups in women (p=0.033) but not in men (n=77 and n=38). Women with the Val allele had a 1.69-fold increased risk for critical CAD (p=0.033). In addition, the presence of Val allele was associated with higher coronary stenosis after adjustment for several confounders only in women with critical CAD (p=0.025). Furthermore, carriers of the Val allele exhibited an increased low-density lipoprotein cholesterol (LDL-C) in men with critical CAD than in those with non-CAD (p<0.05). CONCLUSION: These results suggest that the Val allele of the ITLN1 Val109Asp polymorphism is associated with critical CAD and high LDL-C levels in our study population. Further studies are required to elucidate the effect of Val109Asp polymorphism on CAD pathogenesis.

Association of polymorphisms in the sex hormone genes with the presence and severity of coronary artery disease.

OBJECTIVE: Coronary artery disease (CAD) is an important public health problem worldwide. Therefore, it is important to identify the molecular mechanisms and the candidate gene polymorphisms involved in the development of CAD. In this study, we focused on 2 polymorphisms of the atherosclerosis-related genes, ESR1 and CYP19A1. METHODS: Unselected 339 individuals who underwent coronary angiography were divided into 2 groups: those with normal coronary arteries (≤30% stenosis) and those with critical disease (≥50% stenosis). Individuals were genotyped for CYP19A1 rs10046 C/T and ESR1 rs2175898 A/G polymorphisms using hybridization probes in real-time PCR. In addition, Gensini and SYNTAX scores were assessed. RESULTS: ESR1 polymorphism was significantly associated with CAD in men (p=0.036) via G allele carriage. Multiple logistic regression analyses showed that ESR1 rare allele carriage was associated with CAD presence (Odds ratio=2.12, 95% confidence interval 1.01-4.1, p=0.025), adjusted for age, HDL-C, LDL-C and smoking status in the male group. CYP19A1 rs10046 T allele carriers had a 2.84-fold increased risk for complex CAD in multiple logistic regression analysis (p=0.016). Furthermore, the univariate analysis of variance indicated that T allele carriage of rs10046 polymorphism was associated with increased SYNTAX and Gensini scores (p<0.05). Female patients who were ESR1 G allele carriers with CAD had higher adiponectin levels (p=0.005), whereas HbA1c levels were associated with T allele of CYP19A1 in the CAD group (p=0.004) and male CAD group (p=0.018). CONCLUSION: The CYP19A1 and ESR1 polymorphisms were associated with the presence and severity of CAD. These gene polymorphisms warrant further studies for the elucidation of their contribution to CAD development.

Gender- and obesity-specific effect of apolipoprotein C3 gene (APOC3) -482C>T polymorphism on triglyceride concentration in Turkish adults.

BACKGROUND: Apolipoprotein C3 (APOC3) gene polymorphisms are associated with cardiometabolic risk factors, varying in ethnicities. This study aimed to investigate such association between the APOC3 -482C>T polymorphism and cardiometabolic risk factors in the turkish adult risk factor (TARF) study cohort, stratifying by gender and obesity. METHODS: Randomly selected 1548 individuals (757 male and 791 female, mean age 49.9±11.8 years) were genotyped for -482C>T polymorphism using hybridization probes in a Real-Time PCR LC480 device. RESULTS: The -482TT genotype prevailed 9.9% in men and 11.5% in women. Association between 482C>T polymorphism and dyslipidemia (p=0.036, OR=1.42, 95%Cl=1.02-1.97) was found only in men. Analysis of variance showed that anthropometric and metabolic variables were not differently distributed in APOC3 -482C>T genotypes in the study population. In relation to dyslipidemia and obesity, the -482C>T polymorphism showed significant gender-by-genotype interactions (p<0.01). When the study population was stratified according to gender and obesity, homozygotes for the T allele were associated strongly with (by 45%) elevated fasting triglyceride concentrations in obese men (p=0.009) and homeostatic model assessment (HOMA) index in non-obese women (p=0.013). Furthermore, in the same subgroups, the associations of the fasting triglyceride concentrations and HOMA index with the TT genotype remained after adjustment for risk factors (p<0.05). CONCLUSIONS: APOC3 -482TT genotype is independently associated with elevated fasting triglyceride concentrations in obese men. Presence of obesity seems to be required for this genotype to induce markedly elevated triglycerides. Furthermore, it is associated with the dyslipidemia in men, without requirement of obesity.

Seven patients with Smith-McCort dysplasia 2: Four novel nonsense variants in RAB33B and follow-up findings.

Smith-McCort dysplasia 2 (SMC2) is a rare spondylo-epiphyseal-metaphyseal dysplasia caused by biallelic RAB33B variants. Short trunk dwarfism and radiological findings including the lacy ilia appearance and double bumps of the vertebral bodies are typical features. To date, only eight patients with SMC2 had been reported. The aim of this study is to evaluate the follow-up findings of seven patients from five families with SMC2 and to present four novel variants in RAB33B. The age of diagnosis of the patients was between 4 and 18 years. All patients had variable degrees of short trunk dwarfism with barrel chest, waddling gait, hyperlordosis, genu valgum, elbow and finger joint stiffness, which became more evident with growth. Lacy iliac crest, short ilia with basilar hypoplasia, platyspondyly, dysplastic acetabulum with small and/or laterally displaced femoral heads, and small, irregular carpal bones were detected on skeletal radiographies of all patients. Typical double hump appearance of vertebral bodies was present in patients under 12 years of age, which disappeared after puberty and development of elongated vertebral bodies was also observed. At the time of diagnosis, six patients were able to walk independently; patients who were followed for five to nine years, developed severe hip pain, hip and knee joints stiffness and difficultly of walking after 10 years of age. Only two patients could walk independently during final examination. We detected four novel nonsense variants (p.Gln85Ter, p. Cys48Ter, p. Arg94Ter and p. Gln134Ter) in RAB33B. This study provides important data on long-term skeletal findings of the patients with SMC2.

[Investigating the role of ceramide metabolism-associated CERS5 (LASS5) gene in atherosclerosis pathogenesis in endothelial cells]. / Seramid metabolizmasi ile iliskili CERS5 (LASS5) geninin endotel hücrelerinde ateroskleroz patogenezindeki rolünün arastirilmasi.

OBJECTIVE: Ceramide, the backbone of sphingolipids, is the key component affecting atherosclerotic changes through its important second-messenger role. Previous studies have demonstrated protective role of AMP-activated protein kinase (AMPK) genes in regulating atherosclerosis and hypertension. Ceramide synthase 5 (LASS5 or CERS5) gene has function in de novo synthesis of ceramide, and has indirect effect on AMPK gene. Aim of the present study was to identify role of LASS5 gene in atherosclerosis. METHODS: LASS5 gene-specific small interfering RNA (siRNA)-mediated gene silencing was performed in human umbilical vein endothelial cells (HUVEC) and differential expression of LASS5, AMPK-alpha and AMPK-alpha target genes were analyzed. HUVEC cells were then treated with AMPK activator in order to examine relationship of change in gene expression levels to AMPK activity. RESULTS: Novel physiological function of LASS5 was identified. Downregulation of LASS5 was found to attenuate ceramide production and increase expression of some AMPK target genes in HUVEC. CONCLUSION: This is the first study to demonstrate that LASS5 was involved in negative regulation of atherosclerosis-related genes, such as AMPK-alpha. These preliminary findings provide insight into molecular mechanism of atherosclerosis and are important for development of potential therapeutic agents in the treatment of atherosclerosis.

Sex- and Obesity-specific Association of Aromatase (CYP19A1) Gene Variant with Apolipoprotein B and Hypertension.

BACKGROUND AND AIMS: Gender differences in cardiovascular disease risk have been attributed to sex hormones. The CYP19A1 protein (aromatase) plays a critical role in estrogen biosynthesis and thus affects body fat distribution and regulation. We examined the relationship between polymorphism of the CYP19A1 gene and lipoproteins, body mass index (BMI), insulin levels and HOMA index. METHODS: Randomly selected 2250 Turkish adults (aged 49.7 ± 11.9 years; 48.6% males) were genotyped for CYP19A1 rs10046 polymorphism using hybridization probes in Real-Time PCR LC480 device. RESULTS: Distribution of the CYP19A1 rs10046 polymorphism was 28% (n = 630), 48.3 % (n = 1085) and 23.7% (n = 535) for the CC, CT and TT genotypes, respectively, and the T allele frequency was 0.48. In relation to apolipoprotein (apo)B levels, C homozygosity was associated with higher apoB in non-obese females, contrasting to being so in obese males only, and further in postmenopausal females. CC genotype in females was associated in linear regression analysis by 7.2 ± 3.3 mg/dL higher apoB than CT + TT genotypes, independent of age and BMI. Among premenopausal females, insulin levels (p = 0.007), BMI (p = 0.05) and HOMA index (p = 0.034) were higher in C homozygotes than in T-allele carriers. However, CYP19A1 TT genotype contributed to hypertension at an OR 1.80 (95% CI 1.12-2.91), independently of age, BMI and other confounders, in males alone. CONCLUSION: The CYP19A1 rs10046 polymorphism is associated with cardiovascular risk factors such as circulating apoB, insulin resistance and hypertension in a sex- and obesity-specific manner.