A rare report of H-partially deficient, non-secretor phenotype from India. An Ah like the rèunion and unlike a Para Bombay-Clarifying misinterpretations

Abstract

Background: H-deficient phenotypes are classified as H-deficient non- secretors (Bombay Oh), H-deficient secretors (Para Bombay), and H-partially deficient non-secretors (O _h reunion, A_h and B_h, AB_h).

Report: We report the first case of H-partially deficient non-secretor- the A_h phenotype from India. What makes this report interesting is that they do not fit into the Bombay, or the Para Bombay series of H-deficient phenotypes and these partially deficient non-secretors were exclusively found on Réunion Island, off the East Coast of Africa in 1982. These reunion type phenotypes have not been reported since then and may lead to misinterpretations and confusions when encountered in the current existing laboratory settings especially in the low income (LIC's) and low middle income (LMIC's) countries like our own. Moreover, literature from LMIC and LIC incorrectly uses A_h/B_h for parabombay phenotypes.

Conclusions: H-deficient phenotypes are rare, challenging to identify and assign correct notations. Hence, we have highlighted characteristic differences between H-deficient phenotypes and illustrated a diagnostic laboratory approach to correctly identify and assign notations to them especially in the resource constrained settings.

Keywords: A(h) Phenotype; H-partially deficient non -secretor; Rare blood types.