TABLE 1.
Clinical and functional laboratory test results of the families with congenital erythrocytosis
| Family 1 | Family 2 | Family 3 | |||||
|---|---|---|---|---|---|---|---|
| Proband 1 (F) | Son | Proband 2 (M) | Brother | Sister | Proband 3 (M) | ||
|
Heterozygous BPGM variant Variable |
c.535C > T p.(Arg179Cys) |
c.535C > T p.(Arg179Cys) |
c.269G > A p.(Arg90His) | c.269G > A p.(Arg90His) | None | c.269G > A p.(Arg90His) |
Normal range |
| Hb, g/l | 168 | 200 | 182 | 163 | 156 | 193 |
M: 139–172 F: 119–155 |
| Hct, % | 49 | 57 | 59 | 51 | 48 | 57 |
M: 41–50 F: 36–46 |
| RBC, ×1012/l | 5.5 | 6.5 | 6.7 | 6.0 | 4.9 | 6.3 |
M: 4.2–5.5 F: 3.7–5.0 |
| MCV, fl | 90 | 88 | 88 | 86 | 96 | 91 | 80–97 |
| MCH, fmol | 1.90 | 1.92 | 1.69 | 1.69 | 1.96 | 1.89 | 1.75–2.25 |
| MCHC, g/l | 340 | 350 | 309 | 317 | 329 | 337 | 306–371 |
| ARC, ×109/l | 208 | 221 | 110 | 77 | 134 | 64 | 25–120 |
| WBC, ×109/l | 9.9 | 9.1 | 9.3 | 7.7 | 9.5 | 3.8 | 4.0–10.0 |
| Platelets, ×109/l | 259 | 220 | 189 | 205 | 331 | 201 | 150–450 |
| EPO, u/l | 7 | 7 | 46 a , b | 56 b | NA | 2 |
3–32 4–20 a |
| BPGM activity, u/g Hb | 5.7 | 5.5 | 4.0 | 4.5 | 5.8 | 3.8 | 5.4–8.3 |
| 2,3‐BPG, μmol/g Hb | 25.6 | 21.7 | 11.8 | 14.7 | 23.1 | 14.4 | 28.8 ± 1.7 c |
| P50, mmHg | 20.0 | 20.1 | 18.9 | 19.1 | 22.8 | 18.5 | 24.3 ± 1.4 c |
Abbreviations: 2,3‐BPG, 2,3‐bisphosphoglycerate; ARC, absolute reticulocyte count; BPGM, bisphosphoglycerate mutase; EPO, erythropoietin; F, female; Hb, haemoglobin; Hct, haematocrit; M, male; MCH, mean corpuscular haemoglobin; MCHC, mean corpuscular haemoglobin concentration; MCV, mean corpuscular volume; NA, not available; P50, oxygen pressure at an oxygen saturation of 50% during deoxygenation; RBC, red blood cells; WBC, white blood cells.
Normal ranges of EPO level differ based on local laboratory reference ranges.
EPO levels of Family 2 were based on prior measurements at the referring hospital.
Local laboratory normal ranges of 2,3‐BPG and P50 are presented as mean ± standard deviation based on healthy control samples simultaneously analysed for quality control of the assay (n = 6; in duplo for P50).