Influence of advanced age of maternal grandmothers on Down syndrome

BACKGROUND: Down syndrome (DS) is the most common chromosomal anomaly associated with mental retardation. This is due to the occurrence of free trisomy 21 (92–95%), mosaic trisomy 21 (2–4%) and translocation (3–4%). Advanced maternal age is a well documented risk factor for maternal meiotic nondisjunction. In India three children with DS are born every hour and more DS children are given birth to by young age mothers than by advanced age mothers. Therefore, detailed analysis of the families with DS is needed to find out other possible causative factors for nondisjunction. METHODS: We investigated 69 families of cytogenetically confirmed DS children and constructed pedigrees of these families. We also studied 200 randomly selected families belonging to different religions as controls. Statistical analysis was carried out using logistic regression. RESULTS: Out of the 69 DS cases studied, 67 were free trisomy 21, two cases were mosaic trisomy 21 and there were none with translocation. The number of DS births was greater for the young age mothers compared with the advanced age mothers. It has also been recorded that young age mothers (18 to 29 years) born to their mothers at the age 30 years and above produced as high as 91.3% of children with DS. The logistic regression of case- control study of DS children revealed that the odds ratio of age of grandmother was significant when all the four variables were used once at a time. However, the effect of age of mother and father was smaller than the effect of age of maternal grandmother. Therefore, for every year of advancement of age of the maternal grandmother, the risk (odds) of birth of DS baby increases by 30%. CONCLUSION: Besides the known risk factors, mother's age, father's age, the age of the maternal grandmother at the time of birth of the mother is a risk factor for the occurrence of Down syndrome

Voltammetric determination of catechol based on a glassy carbon electrode modified with a composite consisting of graphene oxide and polymelamine

The authors describe an voltammetric catechol (CC) assay based on the use of a glassy carbon electrode (GCE) modified with a composite consisting of graphene oxide and polymelamine (GO/PM). The modified GCE was characterized by field emission scanning electron microscopy, elemental analysis, Raman spectroscopy and FTIR. Cyclic voltammetry reveals a well-defined response to CC, with an oxidation peak current that is distinctly enhanced compared to electrodes modified with GO or PM only. The combined synergetic activity of GO and PM in the composite also results in a lower oxidation potential. Differential pulse voltammetry (DPV) shows a response that is linear in the 0.03 to 138 μM CC concentration range. The detection limit is 8 nM, and the sensitivity is 0.537 μA⋅μM−1 ⋅cm−2 . The sensor is selective for CC even in the presence of potentially interfering compounds including hydroquinone, resorcinol and dopamine. The modified GCE is highly reproducible, stable, sensitive, and shows an excellent practicability for detection of CC in water samples

Short Article - Isolated cell translocations: are they significant?

BACKGROUND: Cytogenetics study using cultured T-lymphocytes derived from peripheral blood is the easiest way to study human chromosome complement and it is also an excellent method to study chromosomal abnormalities: either structural or numerical. The structural chromosomal abnormalities include translocations, deletions, duplications, ring chromosomes and isochromosomes. AIMS: Cases presenting with multiple congenital anomalies, mental retardation, pregnancy wastage or abnormalities in sexual function are referred to the Division of Human Genetics to rule out chromosomal anomalies. METHODS AND MATERIALS: A total of 70 cases with multiple congenital anomalies, mental retardation, pregnancy wastage or abnormalities in sexual function were studied. About 72 h cultured peripheral lymphocytes subjected to GTG banding were analyzed to look at the chromosome profile. RESULTS: Out of 70 cases of reciprocal translocation, single cell translocations were seen in ten cases (three females; seven males). Looking at the case profile, it was seen that they were referred for mental retardation, bad obstetric history and hypogonadism. It was seen that seven cases (70%) had t(7;14), two (20%) had complex translocations: t(X;9;8) and t(2;10;11), and one (10%) had t(4;21). CONCLUSIONS: Depending on the phenotype, the patients were informed of their abnormality and the need for a look out for the development of any associated problems

Dermatoglyphics in Amenorrhea - qualitative analysis

OBJECTIVE(S): To determine whether any specific dermatoglyphic (DG) features would emerge as markers in amenorrheic subjects. METHOD(S): The study was done on 100 amenorrheic patients and 100 eumenorrheic controls with normal karyotype. Their finger tip patterns, hypothenar patterns, simian crease, Sydney line, interdigital area patterns (qualitative parameters of DGs) were analyzed. Printing method was used. The observations were correlated not only between subjects and controls but also between subjects with normal karyotype and subjects with abnormal karyotype. For statistical analysis percent frequency and chi square test were used. RESULTS: Subjects and controls have shown predominantly loop pattern. It was arch pattern which predominated for the 2nd finger, loop for the 5th finger and whorl for the 4th finger. An increase in the loop pattern in the hypothenar area was observed in subjects, the highest being in patients with abnormal karyotype. Near significant association was seen for the simian crease and Sydney line in subjects. There was significant difference between the patterns in the left 1st interdigital area between controls and subjects with normal karyotype (P=0.05) and in the left 2nd (P=0.009) and 3rd (P=0.04) interdigital areas between controls and subjects with abnormal karyotype. CONCLUSION(S): The qualitative DG parameters could be used in amenorrheic subjects for further referral for karyotyping and counseling