# Familial erythrocytosis type 2 due to VHL germline mutations: a case report and literature review

## TL;DR

This paper reports a rare case of familial erythrocytosis type 2 caused by VHL gene mutations and reviews related literature.

## Contribution

The first reported case in China of ECYT2 caused by compound heterozygous VHL mutations.

## Key findings

- A 31-year-old male with ECYT2 had compound heterozygous VHL mutations (p.P81L and p.N90T).
- Treatment with phlebotomy and aspirin alleviated symptoms without complications.
- ECYT2 is an autosomal recessive disorder with elevated red cell mass and risk of thrombotic complications.

## Abstract

加深对VHL基因复合杂合突变导致的家族性红细胞增多症2型（ECYT2）疾病的认识。

回顾性分析1例ECYT2患者的病例资料，探讨ECYT2的发病机制、临床特点、诊治及预后，并对相关文献进行复习。

男，31岁，因“颜面部和双手潮红29年”入院，全外显子组测序检出VHL p.P81L和p.N90T复合杂合突变，其父母均只携带其中1个杂合突变，为正常表型。结合患者血液学相关化验检查，明确诊断ECYT2，予以红细胞单采术和阿司匹林100 mg/d治疗后，患者因血液淤滞造成的头晕、头痛症状缓解，期间无血栓及出血事件发生。

ECYT2是一类少见的常染色体隐形遗传性疾病，本例VHL基因复合杂合突变所致ECYT2为国内首次报道。其临床特点为红细胞容量升高，血清促红细胞生成素水平正常或升高以及血红蛋白氧亲和力水平正常，易引起血栓和出血性并发症，导致早期死亡。