PEDBASE.org - The Pediatric Database - Detailed information of MAY-HEGGLIN ANOMALY

MAY-HEGGLIN ANOMALY

DEFINITION:

A hereditary disorder characterized by a congenital thrombocytopenia resulting in a tendency for affected individuals to bleed.

EPIDEMIOLOGY:

incidence: rare (at least 83 cases reported)
age of onset:
- infancy
risk factors:
- familial - autosomal dominant
  - chrom.#: ?
  - gene: ?
- M = F

PATHOGENESIS:

1. Background

there are 3 forms of hereditary thrombocytopenia seen in association with giant platelets and inclusion bodies in leukocytes:
- May-Hegglin Anomaly
- Fechtner's Anomaly
- Sebastian Platelet Syndrome

2. Genetic Defect

genetic defect -> abnormal maturation of platelets and fragmen-tation of normal-appearing megakaryocytes in the bone marrow + inclusion bodies in granulocytes
variable phenotypic expression in the bleeding tendency and the degree of inclusion bodies in granulocytes

CLINICAL FEATURES:

1. Hematological Manifestations

most patients are asymptomatic
1. Bleeding (43%)
1. Skin
- easy bruising, petechiae, purpura
2. Mucous Membranes
- recurrent epistaxis, gingival bleeding
- menorrhagia
3. Others
- excessive bleeding following dental extraction, tonsillectomy, and trauma

2. Others

hereditary nephritis
deafness
no evidence of immunosuppression

INVESTIGATIONS:

1. Serum

thrombocytopenia

2. Peripheral Blood Smear

giant bizarre platelets
Dohle Bodies
- basophilic inclusions found within granulocytes (neutrophils, eosinophils, basophils) and occasionally monocytes - represent RNA-containing granules which stain sky blue on Wright stain
- up to 2-5 microns in size and spindle-shaped on EM

MANAGEMENT:

1. Supportive

platelet transfusion for severe bleeding

2. Prognosis

normal life span
some patients at risk for severe bleeds

Pediatric Database - MAY-HEGGLIN ANOMALY

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