Pulmonary hypertension- a novel phenotypic hypothesis of Kabuki syndrome: a case report and literature review.

BACKGROUND: Pediatric pulmonary hypertension (PH) is a serious and rare disease that is often derived from genetic mutations. Kabuki syndrome (KS) is a chromosomal abnormality disease that has its origin in the mutation of lysine methyltransferase 2D(KMT2D). Recent evidence has shown that KMT2D mutations are associated with pediatric pulmonary disorders. However, the relationship between the clinical courses of PH and the KMT2D mutation is reported in extremely few cases. Therefore, in this paper, a case was presented and previous literature was reviewed for better understanding of the correlation between pediatric PH and KMT2D mutations. CASE PRESENTATION: A 3-year-old girl was transferred to our center for severe cough, shortness of breath, fatigue and fever. Physical examination revealed facial deformities and growth retardation. Echocardiography showed a small atrial septal defect (ASD), and right heart catheterization indicated a significant increase in pulmonary vascular pressure and resistance. The genetic test suggested that she had a KMT2D gene mutation. The patient was finally diagnosed with KS. She was given targeted drugs to reduce pulmonary vascular pressure, but the effect was unsatisfactory. CONCLUSIONS: KS can be complicated with multiple organ malformations and dysfunction. With the progress of next generation sequencing, an increasing number of new phenotypes related to KMT2D mutations have been reported. A bold hypothesis is proposed in this article, that is, PH may be a new phenotype associated with KMT2D mutations. It is suggested that KS and PH should be differentiated from each other to avoid delayed diagnosis and treatment in clinical practice. There is no specific drug for KS treatment. The prognosis of children with inherited PH is usually poor, and lung transplantation may increase their survival rates.

[Efficacy of endothelin receptor antagonist bosentan on the long-term prognosis in patients after Fontan operation].

OBJECTIVE: To investigate the long-term effect of bosentan on outcome in patients after Fontan operation. METHODS: Patients after Fontan surgery were randomly divided into bosentan group (B, n = 16) and control group (C, n = 23). Bosentan was applied within 7 days after Fontan surgery as follows: at the first month, 7.8125 mg Bid for patients with body weight ≤ 10 kg; 15.625 mg Bid for patients with body weight between 10-20 kg; 31.25 mg Bid for patients with body weight 20-30 kg and 62.5 mg Bid for patients with body weight > 30 kg. At the second month, the bosentan dose was doubled and Bosentan therapy was continued for more than 1 year. Group C didn't take drugs affecting pulmonary artery pressure. All patients were followed up for 2 years and incidence of mortality, protein losing enteropathy, pulmonary arteriovenous fistulae, 6-minute walk test, heart function were compared between the two groups. RESULTS: After 2 years, mortality tended to be lower in group B compared to group C [6.25% (1/16) vs. 21.8% (5/23), P > 0.05]. Incidence of pulmonary arteriovenous fistulae and protein losing enteropathy were significantly lower in group B than in group C (6.25% vs. 34.78%, P = 0.01;6.25% vs. 39.13%, P = 0.02, respectively) . The results of 6-minute walk test[ (485 ± 44) m vs. (302 ± 183) m] and heart function in group B (3 NYHA III/IV patients in group B vs. 14 NYHA III/IV patients in group C, all P < 0.05) were all better than group C. The concentrations of vasoactive factors such as brain natriuretic peptide (BNP, 279.07 ± 128.17 vs. 457.67 ± 221.30), endothelin (ET, 3.30 ± 0.61 vs. 4.98 ± 1.24) and thromboxane (TXA2, 97.2 ± 24.0 vs. 163.22 ± 24.4) were also significantly lower in group B than in group C (all P < 0.05). Prostacyclin (PGI2) level and incidence of arrhythmias were similar between the two groups. There was no thrombotic event in both groups during follow up. CONCLUSION: Bosentan trerapy in patients post Fontan operation could reduce the incidence of pulmonary arteriovenous fistulae and protein losing enteropathy and improve heart function.