Phenotypic spectrum and genetic analysis in the fatal cases of Schaaf-Yang syndrome: Two case reports and literature review.

ABSTRACT:

Rationale

Schaaf-Yang syndrome, a rare imprinted hereditary disease caused by MAGEL2 variants, manifests as developmental delay/intellectual disability, neonatal hypotonia, feeding difficulties, contractures, and autism spectrum disorder.

Patient concerns

Patient 1 and 2 were infant girls presenting facial dysmorphisms, contractures of interphalangeal joints, neonatal hypotonia, feeding difficulties, congenital heart diseases, and respiratory complications. Besides, Patient 2 presented with delayed psychomotor development.

Diagnosis

Whole-exome sequencing was performed and heterozygous mutations of the MAGEL2 gene were detected in the patients. They were diagnosed as Schaaf-Yang syndrome.

Interventions

The patients received supportive treatment including mechanical ventilation, parenteral nutrition and gastric tube feeding.

Outcomes

Whole-exome sequencing revealed de novo heterozygous c.1996dupC pathogenic mutations in the MAGEL2 gene in the 2 patients. They died due to respiratory failure at the age of 20 days and 98 days, respectively.

Lessons

Our results indicate that MAGEL2 variants can cause congenital heart disease and fatal respiratory complications, broadening the phenotypic spectrum and adding to the fatal cases of Schaaf-Yang syndrome. We highly suggest that the MAGEL2 gene should be added to gene-panels or gene-filters in next-generation sequencing-based diagnostics, which is of great significance for early diagnosis and early intervention of Schaaf-Yang syndrome patients.

SUBMITTER: Chen X 

PROVIDER: S-EPMC7373511 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature