Impact of mevalonate kinase deficiency (MKD) on the quality of life in children and young adults: a national multicentre study

Abstract

Background: MKD is an autosomal recessive disease caused by mutations in the mevalonate kinase (MVK) gene. Aim: To analyze the long term follow-up and health related quality of life (HRQL) in MKD. Methods: MVK gene was analyzed in 950 consecutive patients with periodic fever. 40 MKD patients were identified. Spontaneous disease course was classified as follows: i) resolution (no episodes in the last 6 months), ii) improvement (reduction of more then 30% of fever episodes) iii) stationary iv) worsening (increase frequency of fever episodes or appearance of new major clinical manifestation).The Child Health Questionnaire (CHQ-PF 50) was used to assess the health related quality of life (HRQL). An international sample of 3315 healthy children (52.2% female), with a mean (SD) age of 11.2 (3.8) years constituted the healthy control group. Results: Data on follow-up are available for 31 patients. The mean follow-up was 12.9 years (range 2.3-38.2). Steroid on demand was effective in treating fever episodes. 15 patients showed a significant spontaneous reduction of the frequency of fever episodes. Complete resolution was observed in 3 patients. In 9 patients the disease was stable, in 4 worsened. When compared to healthy age-matched individuals, HRQL of MKD patients was generally affected, particularly for global health, general health perception, mental health, parental-impact emotion and self-esteem (p < 0.001). Conclusions: Even if a relevant percentage of MKD patient show a spontaneous amelioration of the disease, most of them display a tendency towards a persistence of fever episodes that significantly affect their quality of life.