Clinical characteristics and molecular mechanisms of hypoparathyroidism related to GATA3 gene mutation / 中华内科杂志

Objective:To analyze the clinical characteristics and molecular mechanisms of 5 cases of hypoparathyroidism caused by GATA3 gene mutation.Methods:A total of 5 childhood-onset hypoparathyroidism patients with GATA3 mutation were identified from 198 hypoparathyroidism (aged ≤18 years) from 1975 to 2021 in Peking Union Medical College Hospital. Clinical data and biochemical indices of the 5 patients were collected and analyzed retrospectively. Genetic screening was conducted by targeted next-generation sequencing (T-NGS), and bioinformatics analysis was performed to analyze the underline mechanisms.Results:The medium onset age of hypoparathyroidism of the 5 patients was 0.5 (0.1, 1.3) years old, and the time duration from onset to confirmed diagnosis of hypoparathyroidism and hypoparathyroidism- deafness-renal dysplasia syndrome was (7.0±5.2) years and (15.0±5.4) years, respectively. The clinical manifestations included carpopedal spasm accompanied by seizures (5 cases), basal ganglia calcification (5 cases), cataract (1 case), deafness (4 cases), and renal malformations or absence (2 cases). The blood calcium and blood parathormone(PTH) before treatment was (1.65±0.31) mmol/L and (4.64±2.63) ng/L, respectively. The 5 patients carried different heterozygous mutations in GATA3 gene, which caused nonsense mutations, frameshift mutations and splice site mutations, respectively. All the GATA3 gene mutations of the 5 patients are classified as pathogenic or likely pathogenic by the Clin Var database and American College of Medical Genetics and Genomics(ACMG).Conclusions:Attention should be paid to genetic diseases in patients with childhood-onset hypoparathyroidism. The possibility of hypoparathyroidism-deafness-renal dysplasia syndrome should be considered in hypoparathyroidism patients with hearing loss or renal dysplasia. GATA3 gene screening is highly recommended for the confirmation of the diagnosis.

Hypoparathyroidism-sensorineural deafness-renal dysplasia syndrome and mutation anaiysis of GATA3 gene / 中华内分泌代谢杂志

Objective To explore the clinical manifestation of a patient with hypoparathyroidsmsensorineural deafness-renal dysplasia (HDR) syndrome and to sequence the related GATA3 gene of the patient.Methods A 22 year old person with HDR syndrome was reported in regard to clinical manifestation,laboratory examination,and genetic mutation.Some related literatures were reviewed.Results The patient showed tetany,deafness,and positive Chvosteks' and Trousseau' s signs.The initial laboratory studies showed that serum concentration of calcium was lowed and the iPTH level were lower than normal.Binaural pure tone audiometry showed Binaural sensorineural deafness.Colour doppler ultrasound revealed that his right kidney was not observed and the level of creatinine was increased,indicating renal insufficiency.GATA3 mutations on DNA sequence analysis indicated that the 6 exon IVS6-1G-A (G/A heterozygosis splicing),showed the mutation of G to A is in the upstream of the first base in the six exon.After treating with calcium carbonate and vitamin D,the symptoms and signs were improved.Conclusion HDR syndrome is a rare endocrine disease,that should receive more attention in order to avoid missing diagnosis;The IVS6-1G-A as a novel mutation of GATA3 gene,has not been reported so far.

The First Korean Case of HDR Syndrome Confirmed by Clinical and Molecular Investigation

Hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome is a rare condition inherited as autosomal dominant trait and characterized by hypoparathyroidism, sensorineural deafness, and renal dysplasia. HDR syndrome is caused by haploinsufficiency of the GATA3 gene located on chromosome 10p15. Here, we report the case of a 32-day-old Korean male with HDR syndrome. He was presented due to repeated seizures over previous 3 days. The patient was born after 40 weeks of gestation with birth weight of 2930 g, and was the first-born baby of healthy Korean parents. Hypoparathyroidism was first noticed due to seizure. A multicystic left dysplastic kidney and vesicoureteral reflux were detected by ultrasound after birth. Auditory brainstem response (ABR) testing revealed that the patient had moderate sensorineural deafness, with hearing losses of 80 dB at the mid and higher frequencies for both ears. Echocardiography finding revealed secundum atrial septal deftect. Based on biochemical results and clinical findings, a presumptive diagnosis of HDR syndrome was made. GATA3 mutation analysis identified a heterozygous deletion, c.153del (p.Phe51Leufs*144) in exon 1 causing a frameshift mutation, which is a novel de novo mutation. Therefore, we suggest that HDR syndrome should be considered in the differential diagnosis in symptomatic or asymptomatic patients with hypoparathyroidism, and that renal ultrasound or ABR testing be performed to prevent a missed diagnosis. This is the first report on Korean patient with confirmed HDR syndrome with novel mutation.