Fluctuating asymmetry in dermatoglyphics of non-insulin-dependent diabetes mellitus in Bangalore-based population.

Background: The aetiology of NIDDM is believed to be as a consequence of genetic and environmental factors that impair metabolism. While little can be done on the genetic component, much can be done as a preventive measure in NIDDM. Because nothing much can be done prenatally, researchers have resorted to studying physical variables like dermatoglyphics (DGs). Dermatoglyphic patterns form on the finger pad and the palm prenatally and remain unchanged throughout life, thus these features may serve as markers for fetal origin of adult disease like NIDDM. Thus the concept of fluctuating asymmetry (FA) which has been defined as random differences between the right (R) and left (L) sides of a morphological trait has gained prominence in diseases like schizophrenia. When the distribution of R-L differences in a population sample approximates a normal curve with a mean approximately equal to zero, the variance of distributions of R-L difference is a measure of FA. Studies have shown that genetic factors may also have a link to FA in finger and a-b ridge counts. No studies have been reported on FA in NIDDM. FA derived from quantitative parameters in DGs of NIDDM may throw light on fetal origins of an adult disease. Hence this study has been undertaken. Aim: The present study aims at deriving FA from quantitative parameters in DGs of NIDDM compared to controls in the Bangalore based population. Materials and Methods: Bilateral rolled finger and palm prints of 150 NIDDM patients (Males - 75, Females - 75) were compared to 120 controls (Males - 60, females -60) from Bangalore based population. FA measures derived from quantitative parameters (finger ridge counts, a-b ridge counts, main line index and palmar angles) were analysed. Results: Comparisons were made in all parameters between homologous fingers of both hands using Pearson's product moment correlation coefficients (r). The difference in correlation coefficients between cases and controls was calculated using Fisher's Z transformation. 1-r2 an estimate of error variance thus measures FA. FA measures were significantly higher in NIDDM males for the 5th finger (FA=2.04) and for the palmar angle 'dat' (FA=2.24); for the NIDDM female a high FA was found in the 2nd finger (FA=2.17) compared to controls. CONCLUSION: Overall measures of the above ridge counts and angles and their derived measures of FA were prominent features of NIDDM in this sample.

Consanguinity and chromosomal abnormality.

BACKGROUND : Consanguinity is defined as the marriage between close relatives. The deleterious effects associated with consanguinity may be caused by the expression of rare recessive genes inherited from common ancestors. AIMS AND OBJECTIVES : The present study was undertaken to analyze the effect of consanguinity on chromosomal abnormality (CA). METHODS AND MATERIALS : During last 6 years period, a total of 1465 cases with suspected genetic etiology like bad obstetric history, mental retardation, multiple congenital anomalies, Down syndrome, primary amenorrhea and primary infertility was referred to Division of Human Genetics for karyotyping and genetic counseling. The information regarding consanguinity was obtained through pedigree analyzes up to three generations from all the patients. Chi-square test was applied to test the significance. RESULTS : Consanguinity was seen in 427 cases (29.14%), 305 cases were confirmed to have CA, among them 240 (78.7%) had numerical abnormality and 65 (21.3%) had structural abnormality. The presence of consanguinity in CA was seen in 53 cases (17%), including 43 (81.1%) with numerical and 10 (18.9%) with structural abnormality. CONCLUSION : The effect of consanguinity on CA was almost significant ( P < 0.001), whereas the effect was not significant for the type of CA. It may be because of the pooled types of consanguinity as well as the CA. Further information is needed to state categorically that there could be the effect of consanguinity on CA.

Dermatoglyphics in 46, XY females.

Dermatoglyphics is known to be one of the best available diagnostic tools in genetic disorders. This paper aims to find out the diagnostic characteristic dermatoglyphic features in cytogenetically confirmed 46, XY female patients. The total number of patients studied (46, XY females) were 31 and the control consisted of 30 males and 30 females. Dermatoglyphic features, studied and tabulated, were: (a) Finger pattern frequency, (b) total finger ridge count (TFRC), absolute finger ridge count (AFRC), a-b ridge count, 'atd' angle and (c) palmar patterns eg, simian crease, Sydney line, hypothenar pattern, interdigital patterns. Results confirmed significant differences between the 46, XY females and the control groups: (i) 46, XY females had increased ulnar loops but decreased whorls as compared to control males (overall finger pattern frequency). (ii) The right thumb in 46, XY females had less whorls and more ulnar loops than both male and female control groups (individual finger pattern frequency). (iii) 46, XY females had lowered TFRC, AFRC, a-b ridge count than corresponding control groups (both control males and females). Significant differences were not observed for the 'atd' angle, interdigital patterns, hypothenar pattern, simian crease and Sydney line.

Structural chromosomal anomaly in mental retardation.

This article reports the structural chromosomal anomaly in three patients with mental retardation: (i) Proband was a five year old girl with reciprocal retardation (1; 2) (p32; q11) (ii) Proband, female of 14 years. Her karyotype showed translocation (1; 3) (q42; q13). The translocations were de novo in origin (iii) Proband showed variant 13 as the giant satellite over its short arm, and this was paternal in origin. Proband, eighteen months old male child had microcephaly and seizures. These two features may be because of autosomal recessive condition. This report emphasises the need for kayotyping to provide a clear cut diagnosis and appropriate counselling.

Partial 1q and 21p trisomies in a male child due to maternal t(1;21).

Proband 7 years old male child referred for cytogenetic investigation revealed 47, XY + der (21), t(1;21) (q32;q11) mat.

Primary amenorrhea with Xq duplication.

Two female patients aged 16 and 17 years with Turner features short stature, amenorrhea and gonadal dysgenesis were referred for cytogenetic confirmation and counselling. Their karyotypes were 46, X, dup (X) (q13-->q22). The clinical and the cytogenetic picture have been correlated.

Down syndrome associated malformations.

This paper reports the associated malformations and the clinical findings that were observed in 417 cytogenetically confirmed Down Syndrome patients. Among them congenital heart defects have occurred more frequently [75; 17.98%] than osteoarticular malformations [23; 5.52]; eye anomalies [22; 5.27%]; and gastroenterological malformations [n 16; 3.84%]. With regard to prognosis and treatment appropriate counselling has been given to Down Syndrome patients and their families.

Dermatoglyphics in Down's syndrome.

Dermatoglyphic data were obtained from 235 cytogenetically confirmed patients of Down's syndrome. The data were correlated and compared with 230 controls. Printing and transparent adhesive tape photography methods were used to get the dermatoglyphic prints. Patients' total finger ridge counts and 'atd' angles differed significantly from that of the controls. Mostly ulnar loop pattern was observed in the patients. Abnormal dermatoglyphic features such as, simian crease, Sydney line and patterns in the hypothenar and interdigital areas have occurred more frequently in the patients. Dermatoglyphics and the analyses carried out have proved that they are invaluable in their clinical value, in selecting patients of Down's syndrome for cytogenetic analysis.

Cytogenetic investigations in Down syndrome patients & their parents.

A total of 1343 mentally retarded patients referred for cytogenetic evaluation were studied. Of these Down syndrome was confirmed in 365 (21.17%). There were 316 patients of trisomy 21 (86.58%); 21 of mosaicism (5.75%) and 28 of translocation (7.67%). Trisomy 21 patients with chromosomal variants were observed in 17 (4.65%). A 1.37:1 male:female ratio was seen. Karyotyping was also done on 182 parents (of patients of mosaic Down, translocation Down and trisomy 21 with chromosomal variants and in parents with suspected low mosaicism). Mosaic trisomy 21 cell line was found in one mother (0.27%); 6 parents (1.65%) were seen to be translocation carriers and 7 had chromosomal variants (1.92%). Cytogenetic investigations help to give appropriate genetic counselling to patients and their families.