Indian Journal of Medical Sciences Medknow Publications on behalf of Indian Journal of Medical Sciences Trust ISSN: 0019-5359 EISSN: 1998-3654 Vol. 59, Num. 2, 2005, pp. 51-56

Indian Journal of Medical Sciences, Vol. 59, No. 2, February, 2005, pp. 51-56

Original Article

G6PD deficiency in Vataliya prajapati community settled in Surat

Gupte Snehalata C., Patel Pratima U., Ranat Jasmine M.

Surat Raktadan Kendra and Research Centre, B/h. T. and T. V. Middle School, Gopipura, Surat - 395 001
Correspondence Address:Surat Raktadan Kendra and Research Centre, B/h. T. & T. V. Middle School, Gopipura, Surat - 395 001, Gujarat, India Email: srkrc@iqara.net

Code Number: ms05009

Abstract

KEYWORDS: G6PD deficiency, Vataliya Prajapati, G6PD enzyme activity, Hemolytic crisis, Chronic hemolytic anemia

INTRODUCTION

Surat has about 20,000 inhabitants of Vataliya Prajapati community. They have high prevalence of red cell Glucose-6-phosphate dehydrogenase (G6PD) enzyme deficiency. Previous study at our institute, reported 29.8% incidence in them.[1] Molecular genetic studies have revealed the mutation present as G6PD Mediterranean.[2] G6PD deficient subjects can have chronic hemolytic anemia or hemolytic crisis developing after consumption of certain drugs.[3],[4] The screening test for G6PD deficiency, which is based on a qualitative assay, can easily identify the defect among males but in females, by virtue of its X-linked inheritance, reliable results could only be obtained by quantitative assay. However the G6PD enzyme levels in normal males and females are same as in female G6PD gene on one X chromosome is inactive.[5] Since in previous study quantitative assay was not performed to detect the heterozygous status for G6PD deficiency in females, the present study was undertaken to address this aspect. Attempt is also made to study the incidence in Katargam and Amroli; in families having different surnames and as per their native district. Hemoglobin levels will be analyzed to assess the degree of anemia in them and information about their medical history will be evaluated to assess the clinical implication of G6PD deficiency in them.

MATERIALS AND METHODS

After getting Institutional ethical committee′s clearance for the project in August 1999, it was planned to investigate about 10% population of Vataliya Prajapati community in Surat after getting their informed consent. In consultation with the community leader, camps were organized during the period September 1999 to June 2004 (In previous study the sample collection was from 1996 to February 1998) in Amroli and Katargam areas of Surat City, where majority of the members of the Vataliya Prajapati community resides. Information regarding sex, age, family name, native place (village, taluka and district), history of neonatal jaundice, hemolytic crisis or drug induced hemolytic anemia and any other past and present illness etc were recorded through the personal interview conducted. Usually the whole family attended the camp. Separate records were kept about the relationships between the family members. An analysis based on unrelated samples, siblings and children were excluded from the counting.

Blood Samples were collected from 1644 subjects in EDTA bulbs. Hematological parameters were measured using an automatic hematology analyzer (Nihon Khoden) as per the manufacturer′s instructions. Qualitative G6PD deficiency screening was carried out by Nitroblue Tetrazolium (NBT) dye test.[6] Blood was incubated with glucose6-phosphate, nicotinamide adenine dinucleotide phosphate (NADP), NBT dye and phenazine methasulphate. The G6PD enzyme if present, converts NADP to NADPH, which will cause the soluble NBT dye to be reduced to insoluble formazan particles in presence of phenozine metasulphate. Thus normal individual shows a dark brown precipitate within 30 minutes. Deficient subjects or heterozygous females show little or no change or a tan color.

Samples from females and deficient males were subjected to quantitative assay.[7] In this assay conversion of NADP to NADPH per minute is measured on UV spectophotometer. One mole of glucose-6-phosthate can reduce one mole of NADP.

Statistical analysis

Statistical significance was evaluated by χ² test using 2x2 table and mean values were compared by the Student′s "t" test.[8]

RESULTS

A total 12 camps- six in Katargam, five in Amroli and one at our institute were organized. Four hundred and four families had attended these camps and 1644 blood samples were collected at random. Of these, the G6PD deficiency was detected in 359 (22%). Out of 985 males 275 (27.9%) and of 659 females 84 (12.2%) were G6PD deficient. The incidence significantly differed in males and females ( χ²= 53.2, degree of freedom (df) =1, P = <0.001).

G6PD enzyme activity in deficient male and female subjects was found to be 0.181±0.141 international units (IU)/10¹⁰RBC and 0.148±0.118 IU /10¹⁰RBC respectively. The activity in heterozygous deficient and normal females was 1.39±0.311 IU/10¹⁰RBC and 3.75±1.45 IU/10¹⁰RBC respectively. While about 95% (260 out of 275) of the deficient males had the G6PD activity values below 0.5 IU/10¹⁰RBC, the wide majority (73%) (31 out of 43) of the females with heterozygous deficient status displayed the activity between 0.5 to 1.5 IU/10¹⁰RBC.

[Table - 1] gives the incidence of G6PD deficiency in males and females in unrelated samples of present and previous study. The incidence of G6PD deficiency was significantly higher in males compared to females (homozygous deficient) in both the studies (χ²=15.5 and 15.12 respectively; df = 1, P = <0.001). Comparison between present and previous study revealed that the previous study had slightly higher incidence of G6PD deficiency in males but it was statistically insignificant ( χ² = 2.06, df =1, P = 0.1). Previous study revealed slightly lower incidence of homozygous deficient females compared to present study (χ² = 0.25, df =1, P = >0.5).

The data on distribution for G6PD deficiency among various families revealed that in slightly over the half of the families (numbering 211 or 52.2%) both the parents had normal G6PD while remaining 193 families (47.8%) had the defective G6PD gene. Further break-up showed that in 28 families (6.9%), both the parents were G6PD deficient whereas in 22 families (5.4%), the father was deficient with the mother being heterozygous deficient. In remaining families, only one parent had the deficient gene.

Analysis of the samples collected in two regions of Surat did not show statistically significant difference in the incidence of G6PD deficiency (χ²= 0.17, df =1, P > 0.5) as the Vataliya Prajapati residents of Amroli showed incidence of 21.4% (166 out of 776) and those of Katargam 22.2% (193 out of 868).

It was revealed that all the Vataliya Prajapati subjects were originated from two adjacent districts Amreli or Bhavnagar in the Saurashtra region of Gujarat State. Majority of them were from Rajula or Khambha Taluka of Amreli or Mahuva Taluka of Bhavnagar. [Table - 2] displays the incidence of G6PD deficiency amongst the subjects with their origin in Amreli and Bhavnagar districts. G6PD deficiency rate was slightly higher in Amreli with no statistical significance (χ² = 0.4 , df =1, P = 0. 5) for males and for female (χ² = 0.09, df =1, P = 0.75). It is however note worthy that information on the native place could not be reliably recorded for all the subjects with the result, the sample size was too small to make any inference.

The 404 families investigated in this study had 46 different family names. Therefore the number of unrelated subjects having the same surname was too small to carry out statistical analysis. Hence for this particular analysis previous data were pooled with the preset data. The incidence was calculated only when there were more than 20 unrelated subjects with the same family name. The incidence of G6PD deficiency in 11 different family name subjects showed a broad range from 15.2 to 39%.

The medical history of these subjects revealed that malaria, jaundice (presumably hepatitis) and typhoid infections were very common among them. About 20% (255 out of 1285) of the G6PD deficient and 17% of the normal subjects (216 out of 1285) had suffered from these infections in the recent past. Three of the G6PD deficient subjects gave a history Tuberculosis, one of them had hemolytic crisis after the intake of medicines. Of the 17 G6PD deficient subjects suffered from typhoid, three had developed hemolytic anemia with hemoglobin (Hb) values dropped below 8 g/dL. Three of the G6PD deficient children had a history of neonatal jaundice at birth, presumably due to G6PD deficiency.

The Hemoglobin values (mean±SD) with respect to the age of the children are shown in [Table - 3]. The values suggest that the G6PD deficient subjects have mild anemia with the normal subjects showing slightly higher values. Statistical evaluation revealed that G6PD deficient males of all age groups and female deficient children had significantly low mean Hb values with "t" values ranging from 2.0 to 2.8 at 146 to 395 degrees of freedom (P = 0.05).

DISCUSSION

In India, incidence of G6PD deficiency has been reported as 0 to 37% in different castes and communities.[9],[10] The present study substantiates the observation made earlier.[1] As expected both the studies have reported significantly higher incidence of G6PD deficiency in males compared to females because of the sex-linked inheritance. The comparison of the incidence observed among males in the present and previous study reveals that previous study has slightly higher incidence, while it reported lower incidence for females. However, the difference was statistically insignificant. These observations could be attributed to the fact that previous study had used Dichlorophenol-indophenol dye decolorization test for screening, while we have used a different NBT test. Secondly the G6PD activity was not measured in females. Present study reported 24.2% incidence G6PD deficiency among unrelated males and 12.7% among females. The 13.9% of the females with heterozygous G6PD deficient status, together with the homozygous deficient phenotype makes the incidence comparable with males.

The G6PD deficiency incidence in Katargam and Amroli regions of Surat, was comparable. There was no difference in G6PD deficiency rate in Amreli and Bhavnagar districts, the original settlement of the Vataliya Prajapatis. In Amreli, majority of Vataliya Prajapati families were from Rajula and Khambha Talukas while natives of Bhavnagar were mainly from Mahuva Takuka. Variable incidence ranging from 15.2% to 39% was observed in unrelated subjects with different family names. In this community boys generally marry at young age and the bride chosen is usually from the same village. The families showing very high incidence of G6PD deficiency probably have consanguineous marriages. Hence the deficient gene has multiplied.

Literature[11],[12] shows that G6PD enzyme deficient subjects can have chronic hemolytic or drug induced anemia. In majority of the G6PD deficient subjects though the G6PD activity was <0.5 IU/₁₀¹⁰ RBC there was mild or no anemia. In spite of receiving drugs for infections like malaria, jaundice, typhoid and tuberculosis, hemolytic crisis was reported rarely. It appears that G6PD deficient subjects of this community have adjusted to their deficient state and do not have hematological abnormalities. However, before prescribing medicines physician should know of the G6PD status of a patient came from the Vataliya Prajapati community as a safety measure.

ACKNOWLEDGEMENT

References

Copyright 2005 - Indian Journal of Medical Sciences

The following images related to this document are available:

Photo images