Two novel mutations in seven Czech and Slovak kindreds with familial neurohypophyseal diabetes insipidus-benefit of genetic testing

Diagnosis and Treatment of Hereditary Central Diabetes Insipidus in a Swiss Family With a Mutation in the AVP Gene

Hereditary central diabetes insipidus (CDI) is a genetic disorder characterized by polydipsia and polyuria. Most known mutations are located in the arginine-vasopressin (AVP) gene. Here, we describe a Swiss family with an autosomal dominant mutation in the AVP gene region encoding for the carrier protein neurophysin II (P55R). In addition, we discuss the algorithm for diagnosing and treating patients with hereditary CDI based on this Swiss family.

Central Diabetes Insipidus Caused by Arginine Vasopressin Gene Mutation: Report of a Novel Mutation and Review of Literature

Familial neurohypophyseal diabetes insipidus (FNDI) is an autosomal dominant hereditary disorder characterized by severe polydipsia and polyuria that usually presents in early childhood. In this study, we describe a new arginine vasopressin (AVP) gene mutation in an ethnic German family with FNDI and provide an overview of disease-associated AVP-gene mutations that are already described in literature. Three members of a German family with neurohypophyseal diabetes insipidus were studied. Isolated DNA from peripheral blood samples was used for mutation analysis by sequencing the whole coding region of AVP-NPII gene. Furthermore, we searched the electronic databases MEDLINE (Pubmed) as well as HGMD, LOVD-ClinVar, db-SNP and genomAD in order to compare our cases to that of other patients with FNDI. Genetic analysis of the patients revealed a novel heterozygote missense mutation in exon 2 of the AVP gene (c.274T>G), which has not yet been described in literature. We identified reports of more than 90 disease-associated mutations in the AVP gene in literature. The novel mutation of the AVP gene seems to cause FNDI in the presented German family. Similar to our newly detected mutation, most mutations causing FNDI are found in exon 2 of the AVP gene coding for neurophysin II. Clinically, it is important to think of FNDI in young children presenting with polydipsia and polyuria.

Idiopathic central diabetes insipidus in an extreme premature infant: A case report

CONTEXT

Central diabetes insipidus (CDI) is a rare disease during the neonatal period, making it diagnosis difficult and delaying medical treatment.

CASE REPORT

We report here a case of a premature infant born at 26 weeks gestation who, during his 1st month of life, presented persistent hypernatremia with polyuria despite increased fluid supply and low sodium intake. CDI diagnosis was suspected and then confirmed by the therapeutic test with vasopressin analog, in its oral form. Electrolyte disorders were normalized after treatment, which allowed normal weight and height growth with standard fluid supply. Biological and radiological tests were all normal; this CDI was considered idiopathic.

CONCLUSION

Persistent hypernatremia with excessive diuresis should alert to CDI diagnosis.