Publication Date:
2010-11-19
Description:
Abstract 3214 Background: We have identified a kindred in Manitoba and Saskatchewan, Canada, affected by non-immune hemolytic anemia. Red cell morphology, an elevated MCHC and decreased osmotic fragility are consistent with hereditary xerocytosis, a rare hemolytic disorder, for which the causative genetic mutation is unknown. Objectives: To describe the clinical phenotype and inheritance of an uncharacterized chronic hemolytic disorder in a large kindred. Methods: With assistance from each consenting family member, a pedigree was constructed. A focused history was taken and the presence of splenomegaly was assessed by physical examination. Laboratory analysis included a CBC, reticulocyte count, osmotic fragility and peripheral blood film. Biochemical measurements of LDH, ALT, bilirubin, ferritin, haptoglobin, plasma hemoglobin and methemoglobin were performed. Glycolytic enzymes were evaluated in a subset of patients to rule out other rare causes of hemolysis. Results: The family pedigree captured the genetic relations of 342 individuals spanning 5 generations. Consent to participate in the detailed family study was obtained from 137 family members. The average age of the study population was 29 years (range 8 months to 76 years). Laboratory specimens were collected from 26 unrelated spouses and 111 related individuals. Males represented 48% of the studied population. The distribution of reticulocyte counts was distinctly bimodal with no overlap between the two populations, allowing classification of individuals as phenotypically affected or non-affected. The mean percent reticulocyte count of non-affected subjects (related family members and unrelated spouses) was 1.1% (± 0.4, range 0.5–2.3%). Affected subjects had a mean percent reticulocyte count of 9.7% (± 2.6, range 5.3–14.6%). Using this classification, the hemolytic process segregated in an autosomal dominant fashion with complete penetrance. A history of anemia (46 vs. 8%), jaundice (45 vs. 4%), red or brown urine (45 vs. 1%), and either gallstones or cholecystectomy (41 vs. 4%) was more prevalent in affected than unaffected individuals. Episodes of anemia tended to be associated with illness or stress. There was no association between the hemolytic phenotype and neuromuscular, cardiovascular, pulmonary, renal, hepatic, or endocrine disorders. Despite a mean percent reticulocyte count of 9.7% in affected individuals, the mean hemoglobin concentration was not statistically different between affected and unaffected individuals (13.5 ± 1.2 g/dL vs. 13.8 ± 1.4 g/dL, p=0.26). The MCV (96.7 ± 5.5 fL vs. 87.3 ± 5.2 fL, p
Print ISSN:
0006-4971
Electronic ISSN:
1528-0020
Topics:
Biology
,
Medicine
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