A Novel Inherited Mutation in PRKAR1A Abrogates PreRNA Splicing in a Carney Complex Family

Carney complex (CNC) is an autosomal dominant inherited disease, characterized by spotty skin pigmentation, cardiac and cutaneous myxomas, and endocrine overactivity. We report on a Chinese CNC family with a novel mutation in the protein kinase A regulatory subunit 1 (PRKAR1A) gene.

Target-exome sequencing was performed to identify the mutation of PRKAR1A in 2 members of the CNC family.

The proband was a young man with typical CNC, including pigmentation, cutaneous myxomas, cardiac myxoma, Sertoli cell tumour of his left testis, and multiple hypoechoic thyroid nodules. His mother also had CNC with skin pigmentation, cutaneous myxomas, and a cardiac myxoma. Target-exome capture analysis revealed that the proband and the mother carried a novel heterozygous mutation in the exon 6 splicing donor site of PRKAR1A. Sequencing analysis of myxoma messenger RNA revealed that the mutation abrogated exon 6 preRNA splicing, leading to a frameshift starting at Valine 185 and premature translation termination in intron 6. The truncated enzyme lacks the functional cyclic adenosine monophosphate (cAMP) binding domain at the C-terminus, causing PRKAR1A haploinsufficiency.

In this study we report on a novel splicing mutation in the PRKAR1A gene that adds to the genetic heterogeneity of CNC.