Meral Yirmibeş Karaoğuz

An unexpected finding in a child with neurological problems: mosaic ring chromosome 18

Major neurological disorders may accompany rare chromosomal abnormalities. As an example of this rare condition, we present a case with microcephaly, mental retardation, developmental delay, hyperactivity, stereotypic movements, seizures and dysmorphic facial appearance in whom a mosaic ring chromosome 18 was found [45,XX,-18/46,XX,r(18)/46,XX,dicr(18)]. Although ring chromosome 18 phenotype has been known for a long time, this is the third reported patient with a dicentric ring chromosome 18 mosaicism. The presented case will contribute to the identification of the genotype-phenotype correlation in chromosome 18 anomalies.

Gastroschisis with Fetal Chromosomal Abnormality: A Case Report

Gastroschisis is a rare anomaly and it is usually not associated with other syndromic or nonsyndromic anomalies. The first case of gastroschisis with aneuploidy (Turner syndrome) is presented. A fetal huge cystic hygroma was diagnosed by prenatal sonography at 12 weeks of pregnancy and chorionic villi sampling (CVS) was performed. Cytogenetic analysis revealed 45, X0. The pregnancy was terminated by induction of labor at 16 weeks of pregnancy. The female fetus had a big membrane of cystic hygroma surrounding the fetal neck. Additionally, a full abdominal thickness defect with multiple loops of bowel outside the abdomen, which could not be diagnosed on prenatal ultrasound scan, was detected on postnatal examination.

Is cytogenetic diagnosis of 46,XX karyotype spontaneous abortion specimens erroneous? Fluorescence in situ hybridization as a confirmatory technique.

Aim: Performing the standard cytogenetic technique on spontaneous abortion material is still a valuable tool, but finding a normal 46,XX karyotype can confuse investigators and lead to a problem in diagnosis. This is mainly because it is possible for the female or male conceptus to retain contaminating maternal cells. To address this possibility, we used fluorescence in situ hybridization technique (FISH). X (DXZ1: p11.1‐q11.1 region) and Y (DYZ3: p11.1‐q11.1 region) chromosome α‐satellite probes were employed to confirm the karyotypes previously diagnosed as 46,XX by our cytogenetic laboratory, or to verify the occurrence of ‘Y chromosome component’.

The Apolipoprotein E Gene and Taq1A Polymorphisms in Childhood Obesity

Obesity is a multifactorial disease that is influenced by genetic and environmental factors. The apolipoprotein E (Apo E) polymorphism has been reported to influence some lipid profile abnormalities associated with obesity in childhood. In this study, the relationship between the Apo E gene and Taq1A polymorphisms with childhood obesity has been studied. Regarding the Apo E genotypes, e3/4 was the most frequent in both the patient and control groups. Further, there was a significance between the Apo E genotypes with low density lipoprotein and total cholesterol levels. However, no relationship was found between the Taq1A polymorphism and obesity. In conclusion, polygenic inheritance should be kept in mind when dealing with childhood obesity.

Increased frequency of sister chromatid exchanges in peripheral lymphocytes of alcoholics and cigarette smokers

Sister chromatid exchange (SCE) is a sensitive indicator of genotoxicity. In this study we investigated the effects of alcohol consumption and cigarette smoking on the frequency of SCE in cultures of peripheral lymphocytes. The rate was higher in alcoholics who smoked (10.89±2.46) and in smokers (positive controls) (7.64±1.01) than in healthy non‐smokers (negative controls) (6.96±2.18). Statistical analysis suggested that the increases were related to alcohol consumption and cigarette smoking (p<0.05).

Molecular karyotyping of an isolated partial trisomy 11q patient with additional findings.

Isolated partial duplication of the long arm of chromosome 11 is very rare. The main features are dysmorphic facial features, pre/postnatal growth retardation, speech delay, mental retardation, hypotonia, microcephaly, and cardiac, vertebral, limb and genital anomalies. In this case, we report a patient with partial trisomy of 11q13.5→qter due to a de novo rearrangement consisting of the whole X chromosome and part of chromosome 11; 46,X,der(X)(Xqter→Xp22.33::11q13.5→11qter). Additional findings were a separated clavicle, lacrimal duct stenosis and prenatally detected renal hypoplasia. SNP array results revealed a duplication between 11q13.5 and 11qter, measuring 58 Mb, from nucleotide 76,601,607 to 134,926,021. As a result, molecular karyotyping could be performed in such cases in order to establish a definite phenotype-genotype correlation using conventional or molecular cytogenetics techniques.

Comparison of DRD2 rs1800497 (TaqIA) polymorphism between schizophrenic patients and healthy controls: Lack of association in a Turkish sample

Abstract Objective. The association of DRD2 rs1800497 (TaqIA) polymorphisms and schizophrenia has been studied in a number of populations, but the results are contradictory. We aimed to define Taq IA allelic differences between schizophrenic and healthy subjects. Methods. The schizophrenic group consisted of 99 schizophrenic inpatients, diagnosed and treated at Gazi University Hospital Psychiatry Service, the healthy group was composed of 109 subjects who did not suffer from any psychiatric or organic diseases. High molecular weight genomic DNAs were prepared from peripheral venous blood cells by using proteinase K digestion followed by salt extraction method. Target DNA amplification of DRD2 gene (Taq1A, 310-bp region) was performed by polymerase chain reaction (PCR) with the primers 5014 and 971. Results. Of the 208 subjects involved in the study, 98.6% had A1 allele (hetero- or homo-zygote) and 1.4% had A2 allele (homozygote). While all schizophrenia patients had A1 allele, 97.2%, of the healthy subjects (n=106) had A1 allele and there was no significant difference between the groups. Conclusion. This study was the first study related to DRD2 polymorphism conducted in a Turkish schizophrenic patient sample. A great percentage of our sample has A1 allele. Our study could not find a significant association between schizophrenia and DRD2 rs1800497 polymorphism.

Double Aneuploidy in Spontaneous Miscarriages: Two Case Reports and Review of the Literature

The occurrence of double aneuploidy is a relatively rare phenomenon. The clinical presentations are variable depending on the predominating aneuploidy or a combination effect of both. We report the cytogenetic data on products of conception from miscarriages over a period of 5 years. A total of 403 miscarriages were karyotyped and the tissues were villi in all cases. Of 403 cases, 54 cases with single aneuploidy and 2 cases of first-trimester miscarriages with double trisomies were found. These 2 cases with the karyotypes of 48,XXY,+15 and 48,XX,+5,+7 were cited for the first time in this study.

The importance of systematic genetic approach to familial schizophrenia cases and discussion of cryptic mosaic X chromosome aneuploidies in schizophrenia pathogenesis

Abstract Objective. The aim of this study is to contribute to the understanding of schizophrenia genetics by using efficient algorithmic examination techniques including dysmorphic examination, karyotyping, and Fluoresence in situ hybridization (FISH). Methods. In this study we have investigated 20 familial schizophrenia patients from Turkey who had an affected first-degree relative. Dysmorphic examination of the schizophrenia cases and their relatives have been performed. High resolution banding (HRB), specific centromeric, subtelomeric and 22q11.2 region FISH probes were used for genotyping of patients. Results. Dysmorphic examination revealed ear, palate, nose, columella anomalies, and obesity in contributing patients, and the pale skin was noticed. The medical histories and clinical findings of two schizophrenia twins were almost identical. HRB study demonstrated the presence of 46,XX[55]/47,XXX[4]/48,XXXX[1] constitution in a paranoid schizophrenia case and 46,XX[67]/45,X[5] karyotype in her mother. FISH studies aiming subtelomeric chromosomal regions revealed no rearrangements and 22q11.2 regions were intact in all of the patients. Conclusions. The parental gonadal mosaicism lying at the origin of the mitotic aneuploidy may be the reason for mosaic X chromosome aneuploidies in our mother–daughter schizophrenia couple. Mosaic X chromosome aneuploidies may accompany schizophrenia cases and may contribute to pathogenesis of familial schizophrenia.

Prenatal diagnosis of mosaic ring 22 duplication/deletion with terminal 22q13 deletion due to abnormal first trimester screening and choroid plexus cyst detected on ultrasound

We report a rare case of mosaic ring chromosome 22 duplication/deletion in a fetus for whom karyotype analysis was required because of an abnormal finding in the maternal serum screening test and a choroid plexus cyst detected on prenatal ultrasound. Additional prenatal study of the amniotic fluid by fluorescence in situ hybridization was performed and the terminal 22q13.3 deletion was detected on ring chromosome. The final karyotype was 45,XX,‐22[3]/46,XX,r(22)(p11q13.2)[63]/46,XX,idicr(22)(p11q13.2;p11q13.2)[2]dn.ishder(22)(N25+, ARSA‐, ter‐). The pegnancy was terminated. Cytogenetic analysis of the intracardiac blood also revealed ring 22 mosaicism with only one metaphase spread with idicr(22) as the unstable isodicentric rings are subsequently lost from most cells. We discuss the prenatal diagnosis of this rare condition.