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Clinical Characteristics of Pediatric Patients with Congenital Erythrocytosis: A Single Center Study

Background: Although congenital erythrocytosis (CE), an inherited
disorder, impairs pediatric quality of life, physicians often overlook
high hemoglobin (Hgb) levels and its symptoms due to lack of knowledge
of age-adjusted pediatric Hgb levels and CE’s rarity. Methods: In a
retrospective, single-center study, data from hospital records of
patients (<18 years) diagnosed with CE were evaluated.
Results: Forty patients from 39 families (male: female ratio = 7:1) had
been diagnosed with CE in a 20-year period, at a mean age of 15.31 ±
2.49 years (8.34–17.92) and with mean Hgb levels of 17.4 ± 1.34 g/dL
(14.63–23.0). No serum erythropoietin levels exceeded the reference
levels. Although the most common symptom was headache (80.0%), 40.0%
of patients presented with at least one gastrointestinal symptom (e.g.,
nausea, vomiting, abdominal pain, and rectal bleeding), and 75.0%
exhibited plethora. None had leukocytosis, thrombocytosis, abnormal
capillary oxygen saturation, JAK2 mutation, and venous blood gas
analysis and Hgb electrophoresis revealed no abnormalities. While 43.6%
of patients had family histories of CE, 28.2% had 15–48-year-old
relatives who had experienced myocardial infarction, stroke, and/or
sudden death. Six asymptomatic patients were detected incidentally. When
symptoms of hyperviscosity were present, aspirin was prescribed, and
phlebotomy performed. No thrombotic episodes occurred as a result.
Conclusion: To detect CE, physicians should assess Hgb levels in
consideration of normal age-adjusted levels in children. Pediatric
patients with CE may also present with gastrointestinal symptoms.
Although no thrombotic episode occurred among the patients, their family
histories included life-threatening thrombotic episodes, even in
adolescents.