Analysis Of Clinical Phenotype And Genotype Of A Child With Diabetes Insipidus And Literature Review

Objective In order to improve clinicians’ understanding of diabetes insipidus,especially congenital nephrogenic diabetes insipidus,we retrospectively analyzed the disease characteristics and treatment process of a patient with long-term symptoms of polydipsia and polyuria.Methods1.subjects:A child was admitted to the Affiliated Hospital of Qingdao University because of diabetes insipidus.2.methods:(1)We retrospectively analyzed the patient’s clinical data,laboratory and imaging findings,and followed up the patient at the same time;(2)We collected peripheral blood from the patient,his parents and sister.Then we directly sequenced related genes by sequencing technology to find suspicious disease-causing genes,and verified the disease-causing genes of other members.These have been agreed by the medical ethics committee and the parents of the patient.(3)We searched the literature in the Pub Med database,Wanfang and China Knowledge Network database with "congenital nephrogenic diabetes insipidus,hereditary nephrogenic diabetes insipidus,AQP2" as keywords,and reviewed the obtained literatures.Results(1)Boy,10 Y,has had polyuria and polydipsia since childhood.The boy had been diagnosed as "central diabetes insipidus",and no significant improvement in polydipsia and polyuria symptoms treatment with arginine vasopressin.According to the relevant inspection results,the patient was highly suspected of congenital nephrogenic diabetes insipidus.After hydrochlorothiazide treatment,the patient’s symptoms of polyuria and polydipsia are alleviated.(2)The genetic test assisted in the diagnosis of congenital nephrogenic diabetes insipidus caused by the c.727 del G mutation of the AQP2 gene,which was the first new mutation reported in China.The child’s parents and sister are normal,so it is likely to be a newborn mutation and inherited by autosomal dominant.(3)According to the related 62 articles,congenital nephrogenic diabetes insipidus is mostly caused by mutations of two types of genes,AVPR2 and AQP2.There was no significant difference in the clinical manifestations of the patients,and the cause could only be confirmed by genetic testing.Congenital nephrogenic diabetes insipidus is extremely rare,delayed diagnosis is widespread and the prognosis is poor.Conclusions1.In this case,the patient’s genetic test identified congenital nephrogenic diabetes insipidus caused by the c.727 del G mutation of the AQP2 gene,which is the first new mutation reported in China.2.This child with congenital nephrogenic diabetes insipidus delayed diagnosis for nearly 10 years.Literature review found that the disease is extremely rare,and delayed diagnosis in China is very common.The patient lacks effective treatment drugs and has a poor long-term prognosis.Genetic testing plays an important role in determining the cause.