Endocrine Abstracts (2002) 3 OC2

GATA3 mutations in the hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome

MA Nesbit1, MR Bowl1, B Harding1, C Crowe2, A Dobbie3, G Hampson4, I Holdaway5, S Rigden6, J Sampson7 & RV Thakker1


1Molecular Endocrinology Group, Nuffield Department of Clinical Medicine, University of Oxford, OX3 9DU, UK; 2MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, Ohio, USA; 3Department of Clinical Genetics, The Churchill Hospital, Oxford, UK; 4Department of Chemical Pathology, The Guy's, King's College and St Thomas' Hospitals Medical and Dental School, St Thomas' Hospital, London, SE1 7EH, UK; 5Department of Endocrinology, Auckland Hospital, Park Road, Auckland 1, New Zealand; 6Paediatric Renal Unit, Guy's Hospital, St Thomas Street, London, SE1 9RT, UK; 7Institute of Medical Genetics, University of Wales College of Medicine, Cardiff, CF4 4XN, UK


The hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome is an autosomal dominant disorder that is due to a haploinsufficiency of the zinc-finger transcription factor, GATA3 (Nature (2000) 406: 419) whose gene is located on chromosome 10p15. In order to further characterise GATA3 abnormalities we have investigated 6 HDR patients for GATA3 mutations. Leukocyte DNA samples from the 6 probands and an unrelated normal individual were used with 9 pairs of oligonucleotide primers to amplify the 6 exons and 10 intron-exon boundaries of the GATA3 gene. The DNA sequences of both strands of these PCR products were determined. This revealed 2 nonsense mutations, 2 frameshifting deletions, 1 missense mutation and 1 acceptor splice site mutation. These were confirmed in the patients and their affected relatives by allele specific oligonucleotide (ASO) hybridisation, restriction endonuclease or amplification refractory mutation system (ARMS)-PCR analysis. Furthermore, the absence of these changes in 110 alleles from unrelated normal individuals indicated that they were not common sequence polymorphisms. The mutations are predicted to have the following effects: the frameshifting mutation and the nonsense mutation, which are in exon 3, result in the loss of both zinc fingers; the missense mutation, which is in exon 5, disrupts the C-terminal zinc finger; the remaining 3 mutations, which all lie in exon 6, result in the loss of critical basic amino acids adjacent to the C-terminal zinc finger. Electrophorectic mobility shift assays (EMSA) using transfected COS-1 cell nuclear extracts showed that all of these mutations result in the loss of DNA-binding by GATA3. These results further establish the role of this important transcription factor in the embryological development of the parathyroids, inner ear and kidneys, and open the way to elucidating the downstream genes that may function in this developmental pathway

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