A Novel Mutation in the Promoter Region of the ß-Globin Gene: HBB: c.-127G > C.

Novel ß-globin gene mutations are still occasionally being reported, especially when evaluating milder phenotypes. We report here a novel putative mutation in the promoter region of the ß-globin gene and assess its clinical implications. A family, parents and four siblings, with hematological and clinical features suspected of being ß-globin gene mutation(s), were involved in this study. In addition to hematological and clinical evaluations of the whole family, molecular analyses of the ß-globin gene were performed by direct sequencing. Sequencing of the ß-globin gene revealed a novel genomic alteration in the regulatory region of the gene. This novel genomic alteration was defined as HBB: c.-127G > C according to the Human Genome Variation Society (HGVS) nomenclature. Two siblings were found to be carriers of the HBB: c.-127G > C mutation, while the other two siblings were carriers of the codon 8 (-AA) (HBB: c.25_26delAA) deletion of the ß-globin gene. The mother was a compound heterozygote for the codon 8 and HBB: c.-127G > C mutations. Based on hematological and clinical evaluations, we conclude that this novel ß-globin gene promoter region change would be associated with a mild phenotype of ß-thalassemia (ß-thal).

MEFV gene mutations in Turkish children with juvenile idiopathic arthritis.

UNLABELLED: Mutations of the Mediterranean fever (MEFV) gene, which encodes pyrin protein, leads to familial Mediterranean fever (FMF) and a connection between MEFV mutations and rheumatic diseases has been suggested. The aim of this study was to explore the frequency and clinical significance of MEFV mutations in children with juvenile idiopathic arthritis (JIA). In this study, children with JIA, who had no typical symptoms of FMF, were screened for the mutations in exons 2 and 10 of the MEFV gene by direct sequencing. A total of 96 children, 56 girls (58.3%), with a median age of 11 years (2-18 years) were included. Patients were classified according to JIA subgroups as oligoarthritis in 43 (44.8%), rheumatoid factor-negative polyarthritis in 22 (22.9%), rheumatoid factor-positive polyarthritis in 2 (2.1%), systemic arthritis in 12 (12.5%) patients, enthesitis-related arthritis in 16 (16.7%), and psoriatic arthritis 1 (1.04%). A total of 31 children (32.3%) had MEFV mutations: 25 heterozygous, 2 homozygous, and 4 compound heterozygous. There were 22 (11.4%) exon 10 mutations (M694V, R761H, K695R, V726A, R653H) and 15 (7.8%) exon 2 mutations (E148Q, G304R, E148V, T267I). The allele frequencies of MEFV mutations were found to be 19.27%, which is higher than the general population [p = 0.03, (odds ratio (OR):1.93, 95% confidence interval (CI): 1.09-3.41)]. MEFV mutation carrier rates were significantly higher in antinuclear antibody (ANA) negative than in ANA positive patients [p = 0.01, (OR: 0.25, 95% CI: 0.085-0.74)] and in males than in females [p = 0.001, (OR: 0.197, 95% CI: 0.078-0.495)]. Also, there was a statistically significant difference between the MEFV mutation carrier rates and the subgroups of JIA (p = 0.005). CONCLUSION: These findings suggest that mutations of the MEFV gene may be responsible for rheumatic diseases other than FMF, and patients with JIA especially males, ANA negatives, and ERA subgroups should be screened for MEFV gene mutations in countries where FMF is frequent.

The association between intragenic SNP haplotypes and mutations of the beta globin gene in a Turkish population.

Identification of the beta globin gene mutation-related haplotypes is of interest for the delineation of the clinical heterogeneity as well as understanding of the origin and spreading of the beta globin gene mutations. We screened the whole beta globin gene in 197 Turkish patients by direct sequencing and performed Haploview analyses for beta globin gene haplotyping using five common intragenic SNPs; rs713040, rs10768683, rs7480526, rs7946748, and rs1609812. We found 25 different beta globin gene point mutations by sequencing. A Turkish type of inv/del mutation by MLPA and Gap-PCR was also detected with additional studies. The seven most common mutations with higher frequency of 5% were IVS-I-110 (G>A) (35.6%), Hb S(10.6%), IVS-I-6 (T>C) (7.4%), IVS-I-1 (G>A) (6.9%), IVS-II-1 (G>A) (6.9%), Cod8(-AA) (6%), IVS-II-745 (C>G) (5.1%) and accounted for 78.7% of all mutations. We identified seven different haplotypes (Haplotype I-VII) using five intragenic single nucleotide polymorphisms (SNPs) genotyped by sequencing of the beta globin gene. The association between the mutations and the haplotypes was defined for 16 different mutations. We suggest that haplotyping by these five intragenic SNPs will provide useful information about the origin of the mutations and gene flow among as well as the explanation of the clinical heterogeneity.

Pure and complete 12p trisomy due to a maternal centric fission of chromosome 12.

Pure and complete 12p trisomy are rare. Here, we report on a unique patient with trisomy 12p syndrome due to centric fission of maternal chromosome 12. Conventional cytogenetic and fluorescence in situ hybridization (FISH) techniques revealed the proposita's karyotype to be 47,XX,+fis(12)(p10)mat whereas the maternal one was 47,XX,-12,+fis(12)(p10),+fis(12) (q10). This is the first report on centric fission of chromosome 12 leading to stable telocentrics, each with a fully functional centromere. Our observation shows that the centric fission of chromosome 12 can be a new mechanism for generation of a partial centromere and trisomy 12p syndrome.

The association between inherited thrombophilias and pregnancy-related hypertension recurrence.

PURPOSE: The aim of this study was to determine the association between inherited thrombophilias and pregnancy-related hypertension recurrence. METHODS: In this case-control study, blood samples were obtained from patients who had at least two pregnancies complicated with pregnancy-related hypertension (n = 41) and healthy, normotensive pregnancies delivered without any complication (n = 38). Following the DNA extraction, samples were tested for factor V Leiden, prothrombin G20210A and homozygous methylene tetrahydrofolate reductase (MTHFR) C677T mutations using reverse hybridization method. RESULTS: Common inherited thrombophilias were present in 26.8% of women with recurrent pregnancy-related hypertension group and 23.7% of control subjects (odds ratio 1.1; 95% confidence interval, 0.6-1.9). No significant difference was observed between two groups in terms of factor V Leiden, prothrombin G20210A and MTHFR C677T mutations. CONCLUSION: Our data suggest that factor V Leiden, prothrombin G20210A and MTHFR C677T mutations are not associated with pregnancy-related hypertension recurrence.

Prenatal diagnosis of ß-thalassemia and other hemoglobinopathies in southwestern Turkey.

Our aim was to evaluate the prenatal diagnosis of ß-thalassemia (ß-thal) and other hemoglobinopathies in a region with high frequency. After detection by premarital or antenatal screening, 312 patients underwent 420 prenatal diagnostic procedures for 407 fetuses in a 10-year period. Fetal samples were collected by chorionic villi sampling (CVS) in the first trimester and amniocentesis and cordocentesis in the second trimester. Mutation analyses of ß-globin and cytogenetic analyses were performed and the most common mutations detected were: IVS-I-110 (G>A), IVS-II-1 (G>A), IVS-I-6 (T>C) and IVS-II-745 (C>G). Hb S [ß6(A3)Glu→Val, GAG>GTG)] was the most common hemoglobin (Hb) variant with a frequency of 6.3%. Among 407 fetuses, 105 (25.8%) were diagnosed as affected, while 201 (49.4%) were carriers and 101 (24.8%) were normal. Cytogenetic analyses revealed nine fetuses (2.3%) with numerical chromosomal abnormalities as regular or mosaicism. Prenatal diagnosis of common hemoglobinopathies is safe and effective. Performing cytogenetic analysis in excess fetal material is an acceptable option.

The effect of HBB: c.*+96T>C (3'UTR +1570 T>C) on the mild b-thalassemia intermedia phenotype.

Hemoglobin beta (HBB): c.*+96T>C substitution is very rare among ß-globin gene mutations and its clinical significance remains to be clarified. The present study aimed to investigate the role of HBB: c.*+96T>C in the ß-thalassemia intermedia phenotype in a Turkish family. The proband and parents were screened for ß-globin gene mutations via direct sequencing. Hematological and physical examination results were recorded, and correlated according to genotype. The proband was compound heterozygous for Cod 8 (-AA) and HBB: c.*+96T>C, whereas his mother and father were heterozygous for Cod 8 (-AA) and HBB: c.*+96T>C, respectively. The father had almost normal hematological findings, whereas the mother had the typical ß-thalassemia trait phenotype. The proband was diagnosed as mild ß-thalassemia intermedia based on hepatosplenomegaly and hematological findings. To the best of our knowledge this is the first report of HBB: c.*+96T>C mutation in a Turkish family. HBB: c.* 96T>C substitution is a very rare, but clinically relevant ß-globin gene mutation. Additionally, we think that if 1 spouse is a carrier for ß-globin gene mutation the other should be screened for silent mutations, such as HBB: c.*+96T>C mutation of the ß-globin gene, even if she/he does not have any clinical or hematological signs of the ß-thalassemia trait phenotype.

Insertion/deletion polymorphism and serum activity of the angiotensin-converting enzyme in Turkish patients with obstructive sleep apnea syndrome.

This study determined the allelic frequency and genotypic distribution of an angiotensin-converting enzyme (ACE) polymorphism and serum ACE activity in Turkish patients with obstructive sleep apnea syndrome (OSAS). A colorimetric assay measured serum ACE activity in 73 of 97 subjects. Frequencies for II, ID, and DD genotypes were 19.6, 53.6, and 26.8% in the OSAS group and 15, 38, and 47% in the control group, respectively (P = 0.02). The I allele frequency was higher in the OSAS group than in the healthy control group (P = 0.02). Carrying the I allele (II or ID genotypes) increased OSAS risk 2.41 times in the Turkish population. Mean ACE activity was significantly lower in patients with the II genotype than in the DD genotype (P = 0.011), and ACE activity was significantly lower in patients with severe OSAS than in those with mild OSAS (P = 0.006). Our results suggest that II and ID genotypes of the ACE gene increase the risk of developing OSAS in the Turkish population.

Subtelomeric rearrangements of dysmorphic children with idiopathic mental retardation reveal 8 different chromosomal anomalies.

Subtelomeric rearrangements are an important cause of both sporadic and familial idiopathic mental retardation (MR) and/or congenital malformation syndromes. We report on a cohort of 107 children with idiopathic MR and normal karyotype 450-550 band level by GTG banding screened for subtelomeric rearrangements by multiprobe fluorescence in situ hybridization (FISH). In these cases, five patients had de novo deletions (1p deletion was found in 2 cases; 3q deletion, 9p and 9q deletions were found in 1 case each) and four patients had unbalanced rearrangements [der(5)t(5;15)(pter;qter)pat in 2 patients who were siblings, rec(10)dup(10p)inv(10)(p13q26)mat in 1 patient and der(18)t(18;22)(qter;qter) de novo in 1 patient]. Our study confirms that the subtelomeric rearrangements are a significant cause of idiopathic MR with dysmorphic features.

Relationship between SP1 polymorphism and osteoporosis in beta-thalassemia major patients.

BACKGROUND: beta-Thalassemia is an autosomal recessive disease characterized by defective beta-globin chain production. Osteoporosis is an important cause of morbidity in patients with beta-thalassemia major. The pathogenesis of reduced bone mineral density (BMD) is multifactorial. A range of genetics factors have been implicated in other populations of patients with osteoporosis. Polymorphism at the Sp1 binding site of the collagen type I A1 (COLIA1) gene is thought to be an important factor in the development of osteoporosis. METHODS: Alleles S and s, detected by presence of a G or T nucleotide, respectively in a regulatory site of the COLIA1 gene were investigated in 37 beta-thalassemia major patients with osteoporosis and 92 controls without osteoporosis or osteopenia using polymerase chain reaction-restriction fragment length polymorphism. RESULTS: Fifteen and nine beta-thalassemia major patients displayed SS and Ss genotypes, respectively, whereas 13 were found to have an ss genotype. The mean BMD of the beta-thalassemia major patients with ss genotype was similar to those with the Ss and SS genotypes. In the control group, 77 and 15 subjects had SS and Ss genotypes, respectively, with no ss genotype. Allelic and genotypic distribution in patients were significantly different from controls. CONCLUSION: Determining base substitutions at the Sp1 binding site on the COLIA1 gene in early years may be important in preventing osteoporosis in children with beta-thalassemia major.

DNA gains and losses of chromosome in laryngeal squamous cell carcinoma using comparative genomic hybridization.

PURPOSE: A larynx squamous cell carcinoma (LSCC) is one of the most common forms of cancer and may exhibit various complex karyotypes. MATERIALS AND METHODS: We used comparative genomic hybridization (CGH) to analyze DNA gains and losses in 15 squamous cell carcinomas that consisted of 4 glottic, 10 supraglottic, and 1 transglottic localization samples. RESULTS: The majority of the chromosomal alterations detected were gains: 3 samples of LSCCs revealed high level amplification, while 6 samples displayed gains in various chromosomal regions (17p, 3p, 4p, 5p, 6q, 8p, 9p, 14q, 18p and Xq). One sample was found to have losses (chromosomes 15q and 22q) and 5 had normal CGH profiles. CONCLUSION: Many of these gained regions (4p, 5p, 8p, 10q, 18q and Xq) were novel sites, which may harbor oncogene(s) that potentially play an important role in squamous cell tumorigenesis and progression at supraglottic localizations.

Primary atypical teratoid/rhabdoid tumor of the clival region. Case report.

An atypical teratoid/rhabdoid tumor of the central nervous system (CNS) is a rare, aggressive neoplasm found in infants and children that has similar characteristics to CNS primitive neuroectodermal tumors/medulloblastomas. The authors present the case of a patient with an atypical teratoid/rhabdoid tumor and discuss the imaging, histopathological, immunohistochemical, and cytogenetic findings. Tumor cells displayed positive reactions for vimentin, epithelial membrane antigen, and cytokeratin, and they displayed no reaction for glial fibrillary acidic protein, desmin, and actin. The karyotype was 46, XY. The phenotype of an atypical teratoid/rhabdoid tumor appears heterogeneous when examined by histological, immunohistochemical, and genetic analysis. The authors describe the case of a 4-year-old boy who harbored an atypical teratoid/rhabdoid tumor in the clivus, which appeared as a chordoma on neuroimages. To their knowledge, this location of an atypical teratoid/rhabdoid tumor has not been described in the literature.

Combination of Hb Knossos [Cod 27 (G-T)] and IVSII-745 (C-G) in a Turkish patient with beta-thalassemia major.

Beta-thalassemia is the most common disease among hemoglobinopathies in Antalya, Turkey, as well as world-wide. Mutations found in Turkish beta-thalassemia patients constitute a heterogeneous group, consisting mostly of point mutations. Only in very rare cases did deletions or insertions cause affected or carrier phenotypes. Hb Knossos [beta 27 (B9) Ala-Ser] is a rare variant with a normal HbA2 level. In this study, we aimed to investigate the effect of compound heterozygosity for Hb Knossos [Cod 27 (G-T)] and IVSII-745 (C-G). To our knowledge, this is the first report of such a combination related with beta-thalassemia major phenotype in a Turkish family, where reverse dot blot hybridization (RDBH) and DNA sequencing analysis were used. Heterozygous inheritance of the mutation results in mild beta-thalassemia phenotype, whereas homozygous inheritance leads to intermediate beta-thalassemia. As a result, the compound heterozygosity of Hb Knossos with IVSII-745 appears as the cause of the beta-thalassemia major phenotype in our case. The combination of these mutations [Hb Knossos, Cod 27 (G-T), and IVSII-745, C-G] causes the beta-thalassemia major phenotype, and this is important for genetic counseling.

Maternal origin and clinical findings in a case with trisomy 22.

We report a newborn girl with multiple congenital anomalies whose chromosomal analysis showed complete trisomy 22. Her phenotype included microcephaly, epicanthus, hypertelorism, micrognathia, cleft palate, microtia, and preauricular tag. She died in the 24th post-natal hour. Trisomy 22 was shown by fluorescence in situ hybridization technique and the parental origin of the extra chromosome was found to be maternal by DNA microsatellite marker analysis of chromosome 22. Postmortem examination revealed the presence of atrioseptal defect and stasis in the biliary canals. We believe that this patient will contribute to the literature both by clinical findings and short life span associated with maternal origin of extra chromosome 22.

Psychological effects of amniocentesis on women and their spouses: importance of the testing period and genetic counseling.

OBJECTIVE: To evaluate both women's and their spouses' reasons for undergoing amniocentesis, their concerns relating to the procedure as well as their psychological reactions and coping mechanisms during the testing period. METHODS: Eighty-five women undergoing amniocentesis and their spouses took part in the study. The couples completed a questionnaire that provided demographic data and insights into their experiences of amniocentesis. RESULTS: Age was the main reason for undergoing amniocentesis. When they first learned that they were going to undergo amniocentesis, women were more concerned about the potential danger to their fetus than their spouses. Most of participants believed that their pregnancy would continue after amniocentesis. However, they also stated that they were prepared for an abortion. Uncertainty and tension were two significant emotions experienced by couples while waiting for the test results. For the majority of women (80%) and men (42.3%) the strongest support was provided by their spouses during this period. In summary, we can conclude that the test did have a major psychological impact on both women and their spouses, but did not have a negative impact on their coping mechanisms. CONCLUSION: The psychological impact of amniocentesis on women and their spouses does not constitute a major obstacle to their ability to cope. However, a certain number of couples reported feelings of uncertainty, tension and anxiety about fetal injury. We strongly suggest that counseling should be given to high-risk families and that prenatal/antenatal care units must be established.

Gap-PCR Screening for Common Large Deletional Mutations of ß-Globin Gene Cluster Revealed a Higher Prevalence of the Turkish Inversion/Deletion (δß)0 Mutation in Antalya.

OBJECTIVE: Although the calculated carrier frequency for point mutations of the ß-globin gene is around 10% for Antalya Province, nothing is known about the profile of large deletional mutations involving the ß-globin gene. In this study, we aimed to screen common deletional mutations in the ß-globin gene cluster in patients for whom direct DNA sequencing was not able to demonstrate the mutation(s) responsible for the disease phenotype. MATERIALS AND METHODS: Thirty-one index cases selected with a series of selection events among 60 cases without detected ß-globin gene mutation from 580 thalassemia-related cases tested by direct sequencing over the last 4 years in our diagnostic center were screened for the most common 8 different large deletional mutations of the ß-globin gene cluster by gap-PCR. RESULTS: We detected 1 homozygous and 9 heterozygous novel unrelated cases for the Turkish inversion/deletion (δß)0 mutation in our series of 31 cases. Our study showed that the Turkish inversion/deletion (δß)0 mutation per se accounts for 16.6% of the unidentified causative alleles and also accounts for 1.5% of all detected mutations over the last 4 years in our laboratory. CONCLUSION: Since molecular diagnosis of deletional mutations in the ß-globin gene cluster warrants different approaches, it deserves special attention in order to provide prenatal diagnosis and prevention opportunities to the families involved. We conclude that the Turkish inversion/deletion (δß)0, as the most prevalent deletional mutation detected so far, has to be routinely tested for in Antalya, and the gap-PCR approach has valuable diagnostic potential in the patients at risk.

Compound heterozygosity for two beta chain variants: the mildly unstable Hb Tyne (codon 5 Pro→Ser) and HbS (codon 6 Glu→Val).

Compound heterozygosity for Hb Tyne and HbS, that is very rare, was identified by direct DNA sequencing of the beta-globin gene in a Turkish patient. Hematological investigation of a girl at the age of 9 due to the presence of HbS (40.7%) led to the identification of a compound heterozygosity at codons 5-6. This was found to be the result of substitution of cytosine (C) for thymidine (T) at the fifth position and a substitution of adenine (A) for thymidine (T) at the sixth position of the beta globin gene. As a result of these mutations, the order of amino acids at codons 5-6 was changed from Pro-Glu to Ser-Val, respectively. Since the co-inheritance of Hb Tyne and HbS had not been reported in literature before, our case set an example for identification of coinheritance of Hb Tyne and HbS for the first time. Therefore, such cases may be considered as an important example for understanding the structural variants of hemoglobin and may provide important clues for critical amino acids responsible for stabilization of hemoglobin tetrameric structure and genetic counseling.

Comparative genomic hybridization in ganglioneuroblastomas.

The ganglioneuroblastoma are rare lesions with widespread neuronal differentiation that have been classified as intermediate stages between neuroblastoma and ganglioneuroma. To identify overall chromosome aberrations in ganglioneuroblastoma, we performed comparative genomic hybridization. All of the five tumor samples were found to exhibit multiple gains involving different chromosomal regions. Chromosomal gains displayed by chromosomes and chromosome loci were 2p25 approximately pter (60%), 5p15.1 approximately p15.3 (60%), 7 (60%), 13q22 approximately q31 (60%), and 22 (60%), which were detected as minimal common regions in all five tumor samples. Chromosome 22 gain, which had not been reported in neuronal tumors before, and novel site 13q22 approximately q31 may be considered to play an important role in progression and differentiation of ganglioneuroblastoma.

Clinical evaluation of R202Q alteration of MEFV genes in Turkish children.

To date, over 200 alterations have been reported in Mediterranean fever (MEFV) genes, but it is not clear whether all these alterations are disease-causing mutations. This study aims to evaluate the clinical features of the children with R202Q alteration. The medical records of children with R202Q alteration were reviewed retrospectively. A total of 225 children, with 113 males, were included. Fifty-five patients were heterozygous, 30 patients were homozygous for R202Q, and 140 patients were compound heterozygous. Classical familial Mediterranean fever (FMF) phenotype was present in 113 patients: 2 heterozygous and 7 homozygous R202Q, 46 double homozygous R202Q and M694V, and 58 compound heterozygous. The main clinical characteristics of the patients were abdominal pain in 71.5 %, fever in 37.7 %, arthralgia/myalgia in 30.2 %, arthritis in 10.2 %, chest pain in 14.6 % and erysipelas-like erythema in 13.3 %. The frequency of abdominal pain was significantly lower in patients with homozygous R202Q alteration (p = 0.021), whereas patients with heterozygous R202Q mutations, though not statistically significant, had a higher frequency of arthralgia/myalgia (40.0 %, p = 0.05). R202Q alteration of the MEFV gene leads to symptoms consistent with FMF in some cases. This alteration may be associated with a mild phenotype and shows phenotypic differences other than the common MEFV mutations.

A patient with Down syndrome with a de novo derivative chromosome 21.

Pure partial trisomy of chromosome 21 is a rare event. The patients with this aberration are very important for setting up precise karyotype-phenotype correlations particularly in Down syndrome phenotype. We present here a patient with Down syndrome with a de novo derivative chromosome 21. Karyotype of the patient was designated as 46,XY,der(21)(p13)dup(21)(q11.2q21.3)dup(21)(q22.2q22.3) with regard to cytogenetic, FISH and array-CGH analyses. Non-continuous monosomic, disomic and trisomic chromosomal segments through the derivative chromosome 21 were detected by array-CGH analysis. STR analyses revealed maternal origin of the de novo derivative chromosome 21. The dual-specificity tyrosine (Y)-phosphorylation regulated kinase 1A (DYRK1A) and Down Syndrome Critical Region 1 (DSCR1) genes that are located in Down syndrome critical region, are supposed to be responsible for most of the clinical findings of Down syndrome. However, our patient is the first patient with Down syndrome whose clinical findings were provided in detail, with a de novo derivative chromosome 21 resulting from multiple chromosome breaks excluding DYRK1A and DSCR1 gene regions.