aDepartment of Genetic Medicine, Belfast City Hospital
bDepartment of Paediatrics, Ulster Hospital Dundonald
cDepartment of Clinical Genetics, Queens University Belfast, Belfast, UK.
Received 18 October 2018 Accepted 27 February 2019
Correspondence to Caoimhe S. McKenna, MBBS, MSc, MRCPCH, Department of Genetic Medicine, Belfast City Hospital BT9 7AB, UK. Tel: 02895043380; email: email@example.com