Prevalence of ABO & Rh Blood Groups in Colour Vision Defective Punjabi Population
Baljeet Singh Dhillon, Sukhdyal Singh Shergill

ABSTRACT
Colour blindness and ABO & Rh blood groups are inherited entities. Once occurred cannot be changed in life time.  So our aim was to study relationship between ABO & Rh blood and inherited colour blindness. For this, 100 cases of colour blind individuals were examined and were identified and confirmed by testing colour vision of the person by Ishihara's Chart and yarn matching test.  Those found to be suffering from congenital colour blindness were then subjected to ABO & Rh grouping by slide method.  Our results showed statistical significant positive relationship between congenital colour vision defective individual and their ABO & RH blood groups.

INTRODUCTION
The first observation on the existence of difference between the blood of normal individual belonging to the same species was made by Landsteiner in 1900, in human beings.  On the basis of 150 agglutination reactions Landsteiner divided human beings into 3 distinct groups i.e. A, B & O.  The foruth and rarest of all AB was discovered  by Landsteiner's pupils Von Decasteue and Sturli in 1902.  Blood groups represent a system of antigens on the surface of red cells.  These antigens are inherited according to Simple Mendellion Law. The major system ABO and Rh are inherited independently from each other.  During last four decades evidence has been forthcoming that persons belonging to different blood groups  differ in their susceptibility to certain diseases.  Different studies show that there is relationship between blood groups and some diseases i.e. peptic ulcer, certain neoplasm, cancer of stomach and female genitalia, carcinoma urinary bladder, pancreas and salivary glands 2-5.  Association of blood groups have also been studied extensively in various mental disorders6 and congenital disorders etc. Like blood groups, anomalies in colour vision especially congenital ones are also determined by heredity.  Encouraged by above mentioned facts the present study has been under taken with the aim to find the association between ABO blood groups and colour defects in Punjabi population.

MATERIAL & METHODS
100 positive cases of colour defective individuals were identified by screening the persons using Ishihara Chart and yarn matching test.  The subjects suffering from colour blindness were then subjected to ABO and Rh blood grouping by slide method.  A drop of commercially prepared and available anti sera A, B, and Rh was taken and placed on left and right side of glass slides and for Rh on separate glass side.  Anti sera and red cell suspensions were mixed with each other by separate glass rods.  AFter minutes both slides were examined for clumping of red cells, with naked eye and was confirmed with magnifying lens.  Blood grouping of 100 medical students who were not suffering from colour blindness and were healthy individuals, served as control for blood grouping of normal populations.

OBSERVATIONS & DISCUSSION
Distribution of blood groups in control and colour defective population and level of significance by using Chi Square test as shown in table 1 and 2 respectively.

Table - 1

Showing distribution of ABO blood groups in general population

Blood Group Frequency (%age)
A 21%
B 39%
O 31%
AB 9%
Total 100%

Table - 2

Showing distribution of ABO blood groups in colour defective punjabi population

Blood Group No. of Cases %age General Blood Group %age difference
A 10 10 21 -11%
B 37 37 39 -2%
O 26 26 31 -5%
AB 27 27 9 +18%

According to table-2 it is observed that blood group AB shows marked rise in prevalence (18%) where as blood group B & O showed decrease by 2% and 5% and blood group A showed significant decrease by 11%.  This prevalence rate is compared to control group.  However distribution of Rh grouping in control and colour defective Punjabi population did not show any statistical significant results.

REFERENCES

  1. Aird, I. Distribution of ABO blood group and diseases. Proc. of Royal Soc. of Med 1955; 48:139.

  2. Alexander W. ABO blood groups and diseases. Exp. Path 1921; 2:66.

  3. Buchanan JA and Highly ET. Relationship of blood group to disease. Brit. J. Exp. Path. 1921;2:247-55.1

  4. Cruz Coke R. Association of colour blindness and liver cirrhosis. Rey Med Chile 1967;93 (2):519.

  5. Mitra, PN. Blood Group and heredity. Indian J Med Res 1935; 22:495.

  6. Duke E. Congenital deformities. System of Ophthalmology, 1964, 3:666.

  7. Jain AK. Frequency of distribution of blood groups in India. Text book of Physiology 1997;1:117.

Address for Correspondence
Dr. B.S. Dhillon, Deptt. of Ophthalmology,
Govt. Medical College, Amritsar.