Cytogenetic and molecular study in intersex

‘‘Disorders of Sex Development’’ (DSD) is the state of a person whose sex chromosomes, genitalia and/or secondary sex characteristics are determined to be neither exclusively male nor female. The aim of this work was the genetic study of patients with ambiguous genitalia and genetic counseling of these cases. This study was conducted in the period from November 2007 to February 2009. Cases were obtained from the Genetics and Endocrine Units, Pediatric department, Faculty of Medicine, Menoufiya University, Egypt. Thirteen cases with ambiguous genitalia were studied, 10 genetic female and 3 genetic male patients. Their ages ranged from the first week to eight years. All cases were subjected to the following: Detailed history, thorough clinical examination, routine investigations, hormonal, imaging studies, cytogenetic study and molecular study. Sequencing for both the SRY and the CYP21 genes and genetic counseling were performed. Study revealed that among our patients, cases number 2 and 11 were mainly presented as salt losing crisis. Cases 5 and 13 were presented with hirsutism of the external genitalia and upper and lower limbs. Eight cases (61.5%) had a positive consanguinity and Cases 3 and 4 were sisters. Hormonal study revealed that (adrenocorticotropic hormone) ACTH, was within the normal range with a mean 83.14 pg/ml ±53.6 pg/ml for all patients. Serum Cortisol and 17-OHP (17-hydroxyprogesterone) were elevated in all patients. Karyotype using G-banding showed that there were no apparent anomalies in the sex chromosomes. We found four cases (30.8%) with different mutations in the SRY gene at codon Q57R and S143C. As for the CYP21 gene, we found a variety of deletions in size and site within the structure of the gene in 85.4% of cases leading to alteration in the function of the CYP21 gene which ultimately lead to congenital adrenal hyperplasia (CAH) in these cases.Keywords: Developmental Sex Disorders; SRY gene; CYP21 gene; Genetic counseling; Cortisol; 17-Hydroxyprogesteron

Non HLA genetic markers association with type-1 diabetes mellitus

The currently available data identified IDDM1 and IDDM2 as 2 susceptibility loci for type 1 diabetes (T1D). The major histocompatibility complex (MHC)/HLA region referred to as IDDM1 contains several 100 genes known to have a great influence on T1D risk. Within IDDM2, a minisatellite variable number of tandem repeats (VNTR) locus in the insulin gene (INS) promoter region is likely to represent the etiologic polymorphism. The aim of the present work was to study the association between genotypes and susceptibility to T1D among Egyptian diabetic children and their family members. Twenty-five nuclear Egyptian families with 27 children having T1D, aged 3–14 years, their nondiabetic 44 sibs, aged 3–15 years and their parents were included in our study. All studied children were subjected to: detailed history and family pedigree. Thorough clinical examination and anthropometric measurements. Laboratory work up of diabetes including random blood sugar (RBS) and HbA1C. Molecular genetics of INS was studied in four steps; nucleic acid purification, amplification, sequencing and haplotyping using flanking single nucleotide  polymorphisms (SNPs) as surrogate markers for minisatellite alleles identification. Analysis of variant repeat distribution among Egyptian families combined with flanking haplotypes revealed that all our diabetic children had class I alleles of INS; 9 had class IC+, 9 had classID+ and 9 had class ID, while all non-diabetic family members had class III alleles of INS. Therefore the three class I alleles were considered to be equally predisposing to T1D, while class III alleles are dominantly protective. There was significant positive correlations between body massindex (BMI) and both HbA1C and AST liver enzyme among diabetic children with class IC+ but not other alleles; indicating that they need close monitoring of their diabetic control and liver functions beside following specific dietary regimens. It can be concluded that all class I alleles (IC+, ID+ and ID) are equally important susceptibility factors for T1D among Egyptian children, while class III alleles (IIIA and IIIB) are dominantlyprotective. It is concluded also that our diabetic children with class IC+ are an especially endangered subgroup of diabetics. Genotyping for INS-VNTR alleles is recommended for diabetic children as an important step of diagnostic and follow up regimens and for their non-diabetic familymembers for family counseling and early identification of potential diabetics. Further studies of INS-VNTR alleles and HLA haplotypes all over Egypt are recommended to define the Egyptian susceptibility loci for T1D and their relations to the clinical and laboratory findings as an importantnational programs

Chromosome 22 microdeletion in children with syndromic congenital heart disease by fluorescent in situ hybridization (FISH)

Congenital heart diseases (CHDs) are the most common of all birth defects. Congenital heart disease may occur as an isolated malformation or may be part of a syndrome. One of the most common syndromes associated with CHDs is the 22q11.2 microdeletion syndrome, the various conditions associated with del22q11 include DiGeorge syndrome (DGS), velocardiofacial syndrome (VCFS), conotruncal anomaly face syndrome (CTAFS), and others. The abnormalities associated with this syndrome include parathyroid hypoplasia, thymic hypoplasia, immune defect, cleft palate, and abnormal facies. The cardiac defects are usually derived from conotruncus. The aim of the study was to detect the prevalence and the most common or frequent clinical manifestations of chromosome 22q11.2 microdeletion among children with syndromic congenital heart disease. The study was conducted on 20 children with syndromic CHD presenting to the Menoufiya University Hospitals, Egypt. Their ages ranged from 10 days to 12 years. Cytogenetic study and fluorescence in situ hybridization (FISH) were performed in the patients. The study revealed that 2 patients were with chromosomal aberrations [one with 46,XY, add (13)(p13) & the other with 47,XX,+13]. In addition, FISH revealed 4 patients (20%) with 22q11.2 microdeletion syndrome. The congenital heart malformations detected in patients with 22q11.2 microdeletion were somewhat unexpected and included VSD, ASD, PDA, and double outlet right ventricle. The most frequent extracardiac features were hypocalcemia, microcephaly, brain atrophy, epicanthus, low set posteriorly rotated ears, micrognathia, and anemia. The extracardiac features were in some cases subtle. It is concluded that 22q11.2 microdeletion is not uncommon and its manifestations are highly variable. This entails that screening for the microdeletion by FISH should be performed in all patients with syndromic CHD especially those with hypocalcemia, microcephaly, brain atrophy, epicanthus, low set ears, posteriorly rotated ears, micrognathia, and anemia. In addition, patients with minor features and those with non-conotruncal heart disease should not be excluded from the screening for 22 microdeletion.Keywords: Chromosome 22 microdeletion; Syndromic congenital heart disease; DiGeorge syndrome; Hypocalcemia; Velocardiofacial syndrom