Objective: To analyze the clinical, genetic mutation characteristics, and treatment prognosis of type 2A hereditary hemochromatosis (HH) in China.

Methods: Peripheral blood samples and clinical data of patients with primary iron overload were collected through the China Registry of Genetic/Metabolic Liver Disease from June 2015 to November 2023. HH-related genes were detected by Sanger sequencing. Clinical characteristics and gene mutation characteristics of HH patients carrying HJV gene mutations were analyzed.

Results: Among the 37 cases with primary iron overload, ten cases (27.0%, 10/37) had detectable HJV gene mutations, which included four homozygous mutations, five compound heterozygous mutations, and one monoheterozygous mutation. p.Q6H and p.C321X (80.0%, 8/10) were the most common mutated sites. The average age of onset was 30.7±14.7 years. The age of diagnosis was 35.7±16.2 years, with male-to-female ratio of 7:3. Ferritin and transferrin saturation were (5 267±905) ng/ml, and 94.3%±1.2%, respectively. Magnetic resonance imaging showed iron overload in the liver, pancreas, and myocardium. Liver biopsy showed diffuse iron deposition within hepatocytes. All ten cases had elevated transaminases; one case (1/10, 10.0%) had liver cirrhosis; four cases (4/10, 40.0%) had heart failure and arrhythmia; five cases (5/10, 50.0%) had diabetes; six cases (6/10, 60.0%) had hypogonadism; six cases (6/10, 60.0%) had skin pigmentation; and six cases (6/10, 60.0%) had fatigue symptoms. All six cases underwent bloodletting therapy, and ferritin levels dropped to about 100 ng/ml. Two cases of oral administration of the iron chelator deferasirox did not meet the ferritin level standard, and one case died from acute heart failure following a confirmed diagnosis during hospitalization.

Conclusion: The HJV gene may be one of the main pathogenic genes of HH in China. The p.Q6H and p.C321X mutations were one of the hotspot mutations. The onset age of HJV gene-related HH was between 20 and 30 years old, and their condition was severe. Therefore, early bloodletting treatment can have a favorable outcome.