Low oxygen saturation and severe anemia in compound heterozygous Hb Louisville [β42(CD1)Phe→Leu] and Hb La Desirade [β129(H7)Ala→Val]

Figures & data

Table 1. Hematological parameters and globin genotypes of proband and family.

Parameter	I-1		I-2	II-1	II-2
	1st visit	2nd visit
Sex/age	M/30		F/28	M/3	M/1
RBC (×10^12/L)	1.99	2.99	5.48	3.57	5.54
Hb (g/dL)	5.10	8.10	10.9	7.9	11.4
Hct (%)	17.2	27.5	32.0	25.8	33.6
MCV (fL)	86.4	92.0	58.4	72.3	60.7
MCH (pg)	25.6	27.1	19.9	22.2	20.5
MCHC (g/dL)	29.7	29.4	34.0	30.7	33.8
RDW (%)	18.7	21.1	18.8	21.4	17.9
WBC (×10^9/L)	3.06	7.17	8.66	7.70	9.06
PLT (×10^9/L)	79	192	312	173	216
Inclusion body	Positive 20%	Positive 10%	Negative	Negative	NA
Reticulocyte (%)	0.1	3.7	NA	NA	NA
RPI	0.02	1.19	NA	NA	NA
SpO2 (%)	76–80	76–82	NA	76	98
β-Globin genotype	β^LV/β^LD	β^LV/β^LD	β^E/β^E	β^LV/β^E	β^LD/β^E
α-Globin genotype	αα/αα	αα/αα	αα/αα	αα/αα	αα/αα

Hb: hemoglobin; Hct: hematocrit; MCV: mean corpuscular volume; MCH: mean corpuscular hemoglobin; MCHC: mean corpuscular hemoglobin concentration; NA: not available; PLT: platelet count; RBC: red blood cell count; RDW: red cell distribution width; RPI: reticulocyte production index; SpO₂: oxygen saturation; WBC: white blood cell count.

Figure 1. Hb typing by HPLC (A, C, and D) and CE (B). (A) Proband (I-1) showing two overlapping peaks at A- and A2-window. (B) Proband (I-1) showing peaks of Hb A and Hb A₂. (C) Proband’s wife (I-2) showing single peak of Hb A₂/Hb E. (D) Proband’s son (II-1) showing overlapping peak of variant Hb, Hb E, and Hb A₂ and peak of Hb F.

Figure 2. DNA sequencing chromatogram of proband’s β-globin gene. (A) Heterozygous Hb Louisville [β42(CD1)Phe→Leu] as shown by presence of both T and C at codon 42. (B) Heterozygous Hb La Desirade [β129(H7)Ala→Val] as shown by presence of both C and T at codon 129.

Figure 3. Pedigree of the proband and family. Hb E, [β26(B8)Glu→Lys]; Hb LD, La Desirade [β129(H7)Ala→Val]; Hb LV, Louisville [β42(CD1)Phe→Leu].