6-phosphogluconate Dehydrogenase Deficiency

6-Phosphogluconate dehydrogenase deficiency is a hereditary disease characterised by abnormally low levels of the 6-phosphogluconate dehydrogenase enzyme (abbreviated 6PGD). It is a metabolic enzyme involved in the pentose phosphate pathway, especially important in red blood cell metabolism.

Pathology: hematology, hematologic diseases of RBCs and megakaryocytes / MEP (D50-69,74, 280-287)

Red
blood cells

↑

Poly- cythemia	Polycythemia vera

↓

Anemia

Nutritional

Micro-: Iron deficiency anemia
- Plummer-Vinson syndrome

Macro-: Megaloblastic anemia
- Pernicious anemia

Hemolytic
(mostly Normo-)

Hereditary

enzymopathy: G6PD
glycolysis
- PK
- TI
- HK

hemoglobinopathy: Thalassemia
- alpha
- beta
- delta
Sickle-cell disease/trait
HPFH

membrane: Hereditary spherocytosis
- Minkowski-Chauffard syndrome
Hereditary elliptocytosis
- Southeast Asian ovalocytosis
Hereditary stomatocytosis

Acquired

Autoimmune
- WAHA
- CAD
- PCH

membrane
- PNH

MAHA
TM
- HUS

Drug-induced autoimmune
Drug-induced nonautoimmune

Hemolytic disease of the newborn

Aplastic
(mostly Normo-)

Hereditary: Fanconi anemia
Diamond–Blackfan anemia

Acquired: PRCA
Sideroblastic anemia
Myelophthisic

Blood tests

MCV
- Normocytic
- Microcytic
- Macrocytic
MCHC
- Normochromic
- Hypochromic

Other

Methemoglobinemia
Sulfhemoglobinemia
Reticulocytopenia

Coagulation/
coagulopathy

↑

Hyper-
coagulability

primary: Antithrombin III deficiency
Protein C deficiency/Activated protein C resistance/Protein S deficiency/Factor V Leiden
Prothrombin G20210A

acquired:Thrombocytosis
- essential
DIC
- Congenital afibrinogenemia
- Purpura fulminans
autoimmune
- Antiphospholipid

↓

Hypo-
coagulability

Thrombocytopenia	Thrombocytopenic purpura: ITP Evans syndrome TM TTP Heparin-induced thrombocytopenia May-Hegglin anomaly

Platelet function	adhesion Bernard–Soulier syndrome aggregation Glanzmann's thrombasthenia platelet storage pool deficiency Hermansky–Pudlak syndrome Gray platelet syndrome

Clotting factor	Hemophilia A/VIII B/IX C/XI von Willebrand disease Hypoprothrombinemia/II XIII Dysfibrinogenemia

M: MYL

cell/phys (coag, heme, immu, gran), csfs

rbmg/mogr/tumr/hist, sysi/epon, btst

drug (B1/2/3+5+6), btst, trns

Inborn error of carbohydrate metabolism: monosaccharide metabolism disorders (including glycogen storage diseases) (E73–E74, 271)

Sucrose, transport
(extracellular)

Disaccharide catabolism	Lactose intolerance · Sucrose intolerance

Monosaccharide transport	Glucose-galactose malabsorption · Inborn errors of renal tubular transport (Renal glycosuria) · Fructose malabsorption

Hexose → glucose

Monosaccharide catabolism	fructose: Essential fructosuria · Fructose intolerance galactose/galactosemia : GALK deficiency · GALT deficiency/GALE deficiency

Glucose ⇄ glycogen

Glycogenesis	GSD type 0, glycogen synthase · GSD type IV, Andersen's, branching

Glycogenolysis	extralysosomal: GSD type V, McArdle, muscle glycogen phosphorylase/GSD type VI, Hers', liver glycogen phosphorylase · GSD type III, Cori's, debranching lysosomal/LSD: GSD type II, Pompe's, glucosidase

Glucose ⇄ CAC

Glycolysis	MODY 2/HHF3 · GSD type VII, Tarui's, phosphofructokinase · Triosephosphate isomerase deficiency · Pyruvate kinase deficiency

Gluconeogenesis	PCD · Fructose bisphosphatase deficiency · GSD type I, von Gierke, glucose 6-phosphatase