Cullin Proteins ; genetics ; Humans ; Mutation ; Protein-Serine-Threonine Kinases ; Pseudohypoaldosteronism ; genetics ; Vision Disorders ; genetics

An 18-day-old male infant was admitted to the hospital due to recurrent hyperkalemia for more than 10 days. The neonate had milk refusal and dyspnea. The blood gas analysis revealed recurrent hyperkalemia, hyponatremia and metabolic acidosis. Adrenocortical hormone replacement therapy was ineffective. Additional tests showed a significant increase in aldosterone levels. Family whole exome sequencing revealed that the infant had compound heterozygous in the SCNNIA gene, inherited from both parents. The infant was diagnosed with neonatal systemic pseudohypoaldosteronism type I. The infant's electrolyte levels were stabilized through treatment with sodium polystyrene sulfonate and sodium supplement. The infant was discharged upon clinical recovery. This study provides a focused description of differential diagnosis of salt-losing syndrome in infants and introduces the multidisciplinary management of neonatal systemic pseudohypoaldosteronism type I.
Infant ; Infant, Newborn ; Humans ; Male ; Pseudohypoaldosteronism/genetics* ; Hyperkalemia/etiology* ; Hyponatremia/diagnosis* ; Diagnosis, Differential

Bartter-like syndrome encompasses a set of inherited renal tubular disorders associated with hypokalemic metabolic alkalosis, renal salt wasting, hyperreninemic hyperaldosteronism, and normal blood pressure. Antenatal Bartter syndrome, a subtype of Bartter-like syndrome, is characterized by polyhydramnios, premature delivery, life-threatening episodes of fever and dehydration during the early weeks of life, growth retardation, hypercalciuria, and early-onset nephrocalcinosis. Mutations in the bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2) and ATP-sensitive inwardly rectifying potassium channel (ROMK) of the thick ascending limb of Henle's loop have been identified in the antenatal Bartter syndrome. We report the identification of two heterozygous mutations of the gene for Kir 1.1 (ROMK) from an antenatal Bartter syndrome patient who presented at birth with mild salt wasting and a biochemical findings that mimicked primary peudohypoaldosteronism type 1, such as hyperkalemia and hyponatremia, and evolved to a relatively benign course. We have identified amino acid exchanges Arg338Stop and Met357Thr in the gene exon 5 for ROMK by PCR and direct sequencing. Both mutations alter the C-terminus of the ROMK protein, and can affect channel function.
Amino Acid Substitution* ; Bartter's Disease/diagnosis ; Bartter's Disease/embryology ; Bartter's Disease/genetics* ; Codon, Nonsense* ; Diagnosis, Differential ; Exons/genetics ; Female ; Heterozygote ; Human ; Infant, Newborn ; Mutation, Missense* ; Point Mutation ; Potassium Channels/chemistry ; Potassium Channels/genetics* ; Protein Conformation ; Pseudohypoaldosteronism/diagnosis

WNKs (with-no-lysine [K]) are a family of serine-threonine protein kinases with an atypical placement of the catalytic lysine relative to all other protein kinases. The roles of WNK kinases in regulating ion transport were first revealed by the findings that mutations of two members cause a genetic hypertension and hyperkalemia syndrome. More recent studies suggest that WNKs are pleiotropic protein kinases with important roles in many cell processes in addition to ion transport. Here, we review roles of WNK kinases in the regulation of ion balance, cell signaling, survival, and proliferation, and embryonic organ development.
Amino Acid Sequence ; Animals ; Cell Proliferation ; Cell Survival ; Humans ; Hyperkalemia/enzymology/etiology/genetics ; Hypertension/enzymology/etiology/genetics ; Kidney/enzymology ; Models, Molecular ; Molecular Sequence Data ; Mutation ; Neoplasms/enzymology/etiology/genetics ; Protein Structure, Tertiary ; Protein-Serine-Threonine Kinases/*chemistry/genetics/*metabolism ; Pseudohypoaldosteronism/enzymology/etiology/genetics ; Sequence Homology, Amino Acid ; Signal Transduction ; Syndrome