Sideroblastic anemia is a group of inherited and acquired anemias characterized by iron accumulation in erythrocyte precursors, with ring sideroblasts as a key diagnostic feature. The anemias can be hereditary, acquired, or secondary to various factors, each with distinct clinical manifestations and pathophysiology. Laboratory diagnosis includes low hemoglobin levels, characteristic peripheral smear findings, and increased iron levels, while treatment options vary depending on the type and severity of the anemia.

1. SIDEROBLASTIC
ANEMIA
DR MANJULA N MBBS MD
(PATHOLOGY)

2. INTRODUCTION
• Sideroblastic anemias are a group of inherited and
acquired anemias in which iron accumulates in the
mitochondria of erythrocyte precursors.
• Ring sideroblasts are diagnostic feature of this
anemia.

3. ETIOLOGY
ETIOLOGY: 1. HEREDITARY, 2. ACQUIRED AND 3.
SECONDARY CAUSES.
HEREDITARY
(NON- SYNDROMIC)
HEREDITARY (SYNDROMIC)
X-linked
X-linked SA with ring sideroblast and
cerebellar ataxia
Autosomal dominant or
recessive
Myopathy, lactic acidosis and SA
Pearson syndrome
Thiamine- responsive megaloblastic
anaemia

4. ACQUIRED:
• Idiopathic acquired (refractory anemia with ring sideroblasts).
• Associated with previous chemotherapy, irradiation, or in
transition myelodysplasia or myeloproliferative diseases.
SECONDARY:
• DRUGS  Alcohol, Isoniazid, Chloramphenicol.
• RARE  Erythropoietic Protoporphyria, Copper Deficiency Or
Zinc Overload And Hypothermia.

5. PATHOPHYSIOLOGY

6. HEREDITARY SIDEROBLASTIC
ANEMIA PATHOGENESIS

7. ACQUIRED SIDEROBLASTIC
ANEMIA PATHOGENESIS

8. CLINICAL FEATURES
XLSA DUE TO ALAS2 DEFICIENCY:
• Male preponderance
• Iron overload symptoms
• Liver cirrhosis
ARSA DUE TO SLC25A38 MUTATION:
• First weeks or months of life.
• Pyridoxine refractory.
• Carriers unaffected.

9. ABCB7 DEFECT:
• Infants and younger children
• Slow or non-progressive cerebellar ataxia
• Delayed walking
• Dysarthria, intentional tremor, decreased deep tendon reflex,
nystagmus and strabismus.
• Hepatomegaly.

10. GLRX 5 DEFECT:
• Middle age.
• Iron overload, diabetes, darkened skin.
• Hepatomegaly.
MLASA:
• Myopathy, lactic acidosis and SA.
• Short stature, microcephaly, short philtrum and slow gait.
• Severity varies within the family members.

11. TRMA:
• Infancy or childhood.
• Megalobastic anemia, sensorineural deafness and diabetes mellitus.
• Nystagmus, optic atrophy, retinitis pigmentosa, short stature, stroke
and cardiac abnormalities.
PMPS:
• Rare and fatal disorder of infancy.
• Macrocytic anemia, pancreatic exocrine dysfunction and lactic
acidosis.
• Failure to thrive and persistent diarrhea.

12. PRIMARY ACQUIRED SA:
• Late middle age and elderly.
• Breathlessness, fatigue and pallor.
• Hepatomegaly.
• Increased risk of leukemia development.

14. LABORATORY DIAGNOSIS
• HB 
• MCV 
• MCH 
• RDW 
• PERIPHERAL SMEAR Dimorphic (MH/NN), anisopoikilocytosis
with tear drop cells, elongated cells and siderocytes.
• Macrocytosis may be present.
• WBCs- normal,
• Platelets- normal or increased.

15. PERIPHERAL SMEAR

16. BONE MARROW
• Prussian blue stained ringed sideroblast present.
MUSCLE BIOPSY
• Show paracrystalline inclusions within the mitochondria
rigged red fibers.

17. BONE MARROW AND ELECTRON
MICROSCOPY

18. •  S.iron concentration, S.ferritin levels and transferrin
shows increased % of saturation with iron.
• Ferokinetic measurement rapid plasma iron clearance
with  retention of iron isotoes in erythrocytes after 10 to
14 days.
•  Reticulocytes
•  Bilirubin concentration,  in haptoglobin and mild 
IN LDH.
•  Erythroid activity X Age = Degree of iron overload.

19. PRIMARY ACQUIRED (CLONAL):
Clinical- aymptomatic.
• Severe anemia symptoms.
• Infections and bleeding (severe granulocytopenia and
severe thrombocytopenia).
• Iron overload symptoms
• Hepatomegaly and splenomegaly.

21. DIAGNOSIS

22. TREATMENT
HEREDITARY SIDEROBLASTIC ANEMIA:
• Pyridoxine 50 to 200mg/day 2.5mg/day.
• Additional effect with folic acid.
• Thiamine 20-75 mg/ day.
• Iron overload phlebotomy, iron chelation.
• Ablative and Nonmyeloabelative marrow transplantation severe
cases.
SECONDARY CAUSES:
• Remove offending agent.

25. DIFFERENTIAL
DIAGNOSIS

26. PROGNOSIS
• Acquired idiopathic sideroblastic anemia and refractory
anemia have the most favorable outcome among the MDS,
with a median survival of 3 to 6 years and 3% to 12%
incidence of leukemic progression in different series.
• Correlated with three factors: severity of anemia, presence of
thrombocytopenia, neutropenia and karyotype abnormalities.
• Monosomy of chr7 or partial loss of long arm of chr 7 AML
transformation.
• Multiple chr abnormalities and del(20q) leukemia.

27. SUMMARY