Variable phenotype of a null PPP1R13L allele in children with dilated cardiomyopathy

Childhood-onset cardiomyopathy is a genetically heterogeneous group of conditions with several genes implicated. Recently, biallelic loss-of-function variants in PPP1R13L have been reported in association with a syndromic form of dilated cardiomyopathy (DCM). In addition, affected children manifest skin and hair abnormalities, cleft lip and palate (CLP), and eye findings. Here, we delineate the condition further by describing the phenotype associated with a homozygous frameshift variant (p.Arg330 ProfsTer76) in PPP1R13L detected in two sibships in a consanguineous family with six affected children. The index case had DCM and wooly hair, two of his siblings had DCM and CLP while three cousins had, in addition, glaucoma. Global developmental delay was observed in one child. All the children, except one, died during early childhood. Whole exome sequencing and whole genome sequencing did not reveal any other plausible variant. We provide further evidence that implicates PPP1R13L in a variable syndromic form of severe childhood-onset DCM and suggests expanding the spectrum of this condition to include glaucoma. Given the variability of the phenotype associated with PPP1R13-related DCM, a thorough evaluation of each case is highly recommended even in the presence of an apparently isolated DCM.

Spanish Heart Transplant Registry. 31th Official Report of the Heart Failure Association of the Spanish Society of Cardiology

INTRODUCTION AND OBJECTIVES

The present report describes the clinical characteristics and outcomes of heart transplants in Spain and updates the data to 2019.

METHODS

We describe the clinical characteristics and outcomes of heart transplants performed in Spain in 2019, as well as trends in this procedure from 2010 to 2018.

RESULTS

In 2019, 300 transplants were performed (8794 since 1984; 2745 between 2010 and 2019). Compared with previous years, the most notable findings were the decreasing rate of urgent transplants (38%), and the consolidation of the type of circulatory support prior to transplant, with an almost complete disappearance of counterpulsation balloon (0.7%), stabilization in the use of extracorporeal membrane oxygenation (9.6%), and an increase in the use of ventricular assist devices (29.0%). Survival from 2016 to 2018 was similar to that from 2013 to 2015 (P=.34). Survival in both these periods was better than that from 2010 to 2012 (P=.002 and P=.01, respectively).

CONCLUSIONS

Heart transplant activity has remained stable during the last few years, as have outcomes (in terms of survival). There has been a trend to a lower rate of urgent transplants and to a higher use of ventricular assist devices prior to transplant.

Categorized Genetic Analysis in Childhood-Onset Cardiomyopathy

BACKGROUND

Childhood-onset cardiomyopathy is a heterogeneous group of conditions the cause of which is largely unknown. The influence of consanguinity on the genetics of cardiomyopathy has not been addressed at a large scale.

METHODS

To unravel the genetic cause of childhood-onset cardiomyopathy in a consanguineous population, a categorized approach was adopted. Cases with childhood-onset cardiomyopathy were consecutively recruited. Based on the likelihood of founder mutation and on the clinical diagnosis, genetic test was categorized to either (1) targeted genetic test with targeted mutation test, single-gene test, or multigene panel for Noonan syndrome, or (2) untargeted genetic test with whole-exome sequencing or whole-genome sequencing. Several bioinformatics tools were used to filter the variants.

RESULTS

Two-hundred five unrelated probands with various forms of cardiomyopathy were evaluated. The median age of presentation was 10 months. In 30.2% (n=62), targeted genetic test had a yield of 82.7% compared with 33.6% for whole-exome sequencing/whole-genome sequencing (n=143) giving an overall yield of 53.7%. Strikingly, 96.4% of the variants were homozygous, 9% of which were found in 4 dominant genes. Homozygous variants were also detected in 7 novel candidates (ACACB, AASDH, CASZ1, FLII, RHBDF1, RPL3L, ULK1).

CONCLUSIONS

Our work demonstrates the impact of consanguinity on the genetics of childhood-onset cardiomyopathy, the value of adopting a categorized population-sensitive genetic approach, and the opportunity of uncovering novel genes. Our data suggest that if a founder mutation is not suspected, adopting whole-exome sequencing/whole-genome sequencing as a first-line test should be considered.