Incidence of ‘Bombay’ (Oh) Phenotype and Weaker Variants of A and B Antigen in Bombay (India)

Abstract

Abstract. Incidence of Oh and weaker A and B variants was studied in 167,404 Indians in Bombay. Eight out of 17 cases of A variants were due to weak A2, the majority being among AB individuals. Incidence of all weak A is 1:3,300 among persons possessing the A antigen. The actual incidence of A variants deducting weak A2 is approximately 1:6,000 persons having the A antigen. Weak B is observed in 1:9,300 persons possessing the B antigen. Ax‐Bx variants were twice as common as AmBm types. The Oh phenotype is observed in 1:7,600 random persons. The regional and caste distribution of Oh individuals showed that 14 out of 22 of the Oh individuals in the present survey and 33 out of 58 among all Oh cases investigated belonged to south‐west districts of Maharashtra.

Identification of a rare blood group, "Bombay (Oh) phenotype," in Bhuyan tribe of Northwestern Orissa, India

“…Bhatia and Sanghvi[19] calculated the incidence of this phenotype as 1 in 13,000 individuals in Mumbai. Later on, Bhatia and Sathe[20] found an incidence of 1 in 7600 after screening a large number of samples in Mumbai. Gorakshakar et al .,[21] after systematic screening of the rural population from Ratnagiri and Sindhudurg districts of Maharashtra, reported the incidence of the Bombay phenotype as 1 in 4500 in that region, while Moores[22] reported its incidence as 1 in 18,404 amongst Indians settled in South Africa.…”

A profile of rare bloods in India and its impact in blood transfusion service

“…At one point of time, when such a survey was reported,[2] there were a total of 169 cases listed of this phenotype of which 127 came from the West, 30 came from the South, nine from the North, and three from the East of the country. In Mumbai, its incidence was found to be 1 : 7600.…”

“…Among the reported weaker variants of the ABH antigens,[2] weak A is less infrequent than weak B, having a ratio of 3 : 1. Weak H, that give rise to weak A or weak B (as in para-Bombay) phenotype is much rarer than the “Bombay” (Oh) phenotype and occurs with a ratio of 1 : 15.…”

Diminished expression of B antigen mimicking B3 phenotype in a patient with AML-M3: a rare case report

“…The B3 phenotype occurs with a frequency of 1/900 B and 1/1800 A1B in the Chinese population 9 and with a frequency of 1:116,667 in French donors 10 . Reports from India show the frequency of the weak B phenotype to be 1:86,687 among the donors of north India 10 and 1:24,000 from Bombay 11 . However the exact frequency is not known.…”