Table 2.

The hereditary macrothrombocytopenias.

DisorderFeatures
(Modified from
Rodriguez et al.
Mayo Clin Proc
.
2003
;
78
:
1416
–1421
.) 
May-Heggelin anomaly Autosomal dominant
 Very large platelets
 Normal platelet function
 Leukocyte inclusions
 MYH9 mutation 
Sebastian syndrome Autosomal dominant
 Near normal platelet function
 Granulocyte inclusions distinct from those in May-Heggelin
 MYH9 mutation 
Fechtner Syndrome Autosomal dominant
 Granulocyte inclusions like those in Sebastian syndrome
 Nephritis, deafness, cataracts
 MYH9 mutation 
Epstein syndrome Autosomal dominant
 Platelet dysfunction
 No granulocyte inclusions
 Nephritis and deafness
 MYH9 mutation 
Eckstein syndrome Like Epstein Syndrome but normal
 Platelet function
 MYH9 mutation 
Bernard-Soulier syndrome Autosomal recessive
 Absent GpIb/IX complex
 Severe platelet adhesion defect 
Grey Platelet syndrome Autosomal recessive inheritance
 Absence of platelet a granules
 Mild platelet dysfunction 
Giant platelets with the velocardiofacial syndrome Autosomal recessive inheritance
 Defective GpIb/IX
 Mutation/Deletion at 22q11.2
 Conotruncal heart defects
 Severe learning disability 
Giant platelets and mitral valve insufficiency Autosomal recessive inheritance
 Mild bleeding
 Absent collagen receptor (GpIa/IIa)
 Decreased platelet agg to ADP, thrombin
 Arachidonate 
Familial macrothrombocytopenia Autosomal dominant and GpIV deficiency
 Defect/absence GpIV
 Reduced aggregation to ADP and epinephrine
 Mild bleeding
 No neutrophil inclusions 
Montreal platelet syndrome Autosomal dominant inheritance
 Spontaneous platelet aggregation
 Prolonged bleeding time 
Enyeart syndrome Autosomal recessive inheritance
 Mild to severe bleeding
 Small inclusions in platelets 
Mediterranean macrothrombocytopenia Pathogenesis unclear
 Restricted to Greeks and Italians
 Some are heterozygous Bernard-
 Soulier carriers
 Many have the Bolzano variant of
 GpIbα
 Val156Ala 
DisorderFeatures
(Modified from
Rodriguez et al.
Mayo Clin Proc
.
2003
;
78
:
1416
–1421
.) 
May-Heggelin anomaly Autosomal dominant
 Very large platelets
 Normal platelet function
 Leukocyte inclusions
 MYH9 mutation 
Sebastian syndrome Autosomal dominant
 Near normal platelet function
 Granulocyte inclusions distinct from those in May-Heggelin
 MYH9 mutation 
Fechtner Syndrome Autosomal dominant
 Granulocyte inclusions like those in Sebastian syndrome
 Nephritis, deafness, cataracts
 MYH9 mutation 
Epstein syndrome Autosomal dominant
 Platelet dysfunction
 No granulocyte inclusions
 Nephritis and deafness
 MYH9 mutation 
Eckstein syndrome Like Epstein Syndrome but normal
 Platelet function
 MYH9 mutation 
Bernard-Soulier syndrome Autosomal recessive
 Absent GpIb/IX complex
 Severe platelet adhesion defect 
Grey Platelet syndrome Autosomal recessive inheritance
 Absence of platelet a granules
 Mild platelet dysfunction 
Giant platelets with the velocardiofacial syndrome Autosomal recessive inheritance
 Defective GpIb/IX
 Mutation/Deletion at 22q11.2
 Conotruncal heart defects
 Severe learning disability 
Giant platelets and mitral valve insufficiency Autosomal recessive inheritance
 Mild bleeding
 Absent collagen receptor (GpIa/IIa)
 Decreased platelet agg to ADP, thrombin
 Arachidonate 
Familial macrothrombocytopenia Autosomal dominant and GpIV deficiency
 Defect/absence GpIV
 Reduced aggregation to ADP and epinephrine
 Mild bleeding
 No neutrophil inclusions 
Montreal platelet syndrome Autosomal dominant inheritance
 Spontaneous platelet aggregation
 Prolonged bleeding time 
Enyeart syndrome Autosomal recessive inheritance
 Mild to severe bleeding
 Small inclusions in platelets 
Mediterranean macrothrombocytopenia Pathogenesis unclear
 Restricted to Greeks and Italians
 Some are heterozygous Bernard-
 Soulier carriers
 Many have the Bolzano variant of
 GpIbα
 Val156Ala