Baylor University Medical Center Proceedings April 2017 - 184

A rare hemoglobin variant, Hb Belliard
Stacey Murthy, MD, and Raul Benavides, MD

There are many documented variants of
hemoglobin; however,
other than a limited
number (such as sickle
cell disease), very few
are known to have any
clinical significance.
As advances in detection and identification
continue through gel
electrophoresis, capillary electrophoresis,
and DNA sequencing,
more rare variants are Figure 1. Hemoglobin electrophoresis: (a) test for the patient described here; (b) a more typical result.
identified. Without case
reporting, the significance of these variants will remain unknown
DISCUSSION
Hemoglobin is a tetrameric protein that is predominantly
or continue to be thought of as insignificant. Here we report a rare
composed of HbA (2 α and 2 β chains) (Figure 1b). Most
hemoglobin variant, Hb Belliard, which was detected in a 68-year-old
mutations are caused by a point mutation that substitutes one
Indian immigrant to the United States. He presented with elevated
amino acid for another in one of the globins. The majority of
hemoglobin and was found to have a unique peak on capillary elechemoglobin variants occur in the beta globin chains (such as
trophoresis. The specimen was sent for sequencing and was subsesickle mutation); however, some mutations are known to occur
quently found to have Hb Belliard. Currently, Hb Belliard is thought
in the alpha chains (such as Hb Belliard). Over 80 diseases
to be insignificant.

CASE DESCRIPTION
A 68-year-old Indian man who immigrated from
Mumbai, India, to Garland, Texas, in 1980 presented with
weakness, fatigue, and morning nausea. His hemoglobin
was 17.1 g/dL, and 3 months later it was 17.2 g/dL. A peripheral blood smear revealed signiﬁcant microcytosis with
moderate hypochromasia and a moderate number of target
cells. Hemoglobin electrophoresis revealed 83.9% Hb A,
5.6% Hb A2, and 10.5% Hb Bart's or variant (Figure 1a).
To further classify the Hb Bart's/variant, the specimen was
sent to ARUP Laboratories for gene sequencing and identiﬁcation. The variant, Lys56Asn, was detected on the HbA1
gene, corresponding to the Hb Belliard variant. Additional
testing also found that the patient had a JAK2 mutation and
β0 thalassemia.
184

have been identiﬁed that are due to substitutions that result in
changes to the structure of the hemoglobin; some alter function
and others are silent (1, 2). As each mutation was discovered,
it was assigned a letter as its designation. As more mutations
at the same position were identiﬁed, nomenclature started to
include the name of the city where it was discovered (2, 3). In
the modern laboratory, capillary electrophoresis has replaced
traditional gel electrophoresis due to its much higher resolution,
producing faster, more accurate results. As more mutations are
elucidated, it becomes increasingly diﬃcult to identify them,
and more sophisticated ways of diﬀerentiating the mutations are
From the Department of Pathology, Baylor University Medical Center at Dallas,
Texas.
Corresponding author: Stacey Murthy, MD, Department of Pathology, Baylor
University Medical Center at Dallas, 3500 Gaston Avenue, Dallas, TX 75246
(e-mail: Stacey.murthy@gmail.com).
Proc (Bayl Univ Med Cent) 2017;30(2):184-185

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