Erythrocyte enzyme study
. | Patient . | Normal range . |
|---|---|---|
| Enzyme levels | ||
| Erythrocyte aldolase | 0.3 U/g Hb (maternal, 1.5 ± 0.2 U/g Hb) | 1.3-2.8 U/g Hb |
| Erythrocyte LDH | 360 U/L (maternal, 260 U/L) | 90-180U/L |
| RBC enzyme levels, U/g Hb | ||
| Glucose phosphate isomerase | 69 | 48-90 |
| Hexokinase | 3.8 (↑) | 1.0-2.5 |
| Phosphoglycerate kinase | 196 (↑) | 141-179 |
| Pyruvate kinase | 40.5 (↑) | 9.0-22.0 |
| Phosphofructokinase | 5.7 | 3.0-6.0 |
| Plasma enzyme levels, U/L | ||
| Aldolase | 6.2,* 1 (↓) | 3-12 |
| Creatine phosphokinase | 13 800 (↑ ↑) | 4-150 |
. | Patient . | Normal range . |
|---|---|---|
| Enzyme levels | ||
| Erythrocyte aldolase | 0.3 U/g Hb (maternal, 1.5 ± 0.2 U/g Hb) | 1.3-2.8 U/g Hb |
| Erythrocyte LDH | 360 U/L (maternal, 260 U/L) | 90-180U/L |
| RBC enzyme levels, U/g Hb | ||
| Glucose phosphate isomerase | 69 | 48-90 |
| Hexokinase | 3.8 (↑) | 1.0-2.5 |
| Phosphoglycerate kinase | 196 (↑) | 141-179 |
| Pyruvate kinase | 40.5 (↑) | 9.0-22.0 |
| Phosphofructokinase | 5.7 | 3.0-6.0 |
| Plasma enzyme levels, U/L | ||
| Aldolase | 6.2,* 1 (↓) | 3-12 |
| Creatine phosphokinase | 13 800 (↑ ↑) | 4-150 |
Normal ranges are represented as ± 2 SD from the mean.
Enzyme activities of RBC aldolase A and LDH were measured in EDTA (ethylenediaminetetraacetic acid)–anticoagulated blood from patient and mother at 30°C. Patient's RBC aldolase level is markedly decreased. Normal enzyme ranges are derived from the Internal Committee for Standardization in Hematology.6 Patient RBC and plasma enzyme levels were obtained at age 48 months. Markedly elevated CPK levels are noted (↑ ↑). Glycolytic enzyme levels aside from aldolase A are either normal or slightly elevated (↑), as expected in hemolytic anemia. Plasma aldolase is derived primarily from muscle. The low level (↓) in the face of marked CPK elevation supports the diagnosis of muscle aldolase deficiency.
Unexpected “normal” value