Unusual presentation of a five-month-old boy with NaPi2a homozygous mutation without hyperphosphaturia: Case report and review of the literature.

Deletions of the NaPi2a gene and mutations in the SLC34A gene should be considered in patients with atypical presentation, without phosphaturia, with mild hypo to normal phosphatemia, and nephrocalcinosis.

One-month-old girl presenting with pseudohypoaldosteronism leading to the diagnosis of CDK13-related disorder: a case report and review of the literature.

BACKGROUND: It is not uncommon that an infant with a disease of unknown etiology is presented to a physician. Facial dysmorphic features lead to a different diagnosis. It is a challenge to link the presentation to the newfound diagnosis. CASE PRESENTATION: A 37-day-old Yemenite Jewish girl was presented to our institution with a clinical picture of pseudohypoaldosteronism due to abnormal facial features and a psychomotor developmental delay. Further investigation led to the diagnosis of CDK13-related disorder. According to the literature, CDK13 has a key role in the cell cycle, but no interference with the aldosterone signaling pathway or electrolyte balance was described. No mutations in the previously described gene NR3C2 (cytogenetic location 4q31.23), encoding the mineralocorticoid receptor, were found. Although the clinical presentation corresponded to pseudohypoaldosteronism type 1, we could not genetically confirm this. CONCLUSIONS: Probably pseudohypoaldosteronism was a coincidental finding in this girl with a CDK13 mutation, but because only limited information is known about CDK13-related disorders, further investigation could be more informative to clarify this presentation.