Pseudohypoaldosteronism Type 1B and Cohen Syndrome: Novel Mutation, Unusual Combination, and Presentation

Pseudohypoaldosteronism type 1 (PHA1) is a rare inherited disorder of resistance to aldosterone and presents with hyponatremia, hyperkalemia, and metabolic acidosis. Cohen syndrome (CS) is another rare inherited disease. Concurrent presentation with pseudohypoaldosteronism makes it so extraordinary and implies more challenges for clinicians. We report a case of a female with Cohen syndrome (novel mutation) and systemic pseudohypoaldosteronism, as well as the challenges we have encountered in the management of this patient.

[Psychomotor retardation with neutropenia for more than one year in a toddler]

A boy was admitted at the age of 17 months. He had psychomotor retardation in early infancy. Physical examination revealed microcephalus, unusual facies, and a single palmar crease on his right hand, as well as muscle hypotonia in the extremities and hyperextension of the bilateral shoulder and hip joints. Genetic detection identified two pathogenic compound heterozygous mutations, c.8868-1G>A (splicing) and c.11624_11625del (p.V3875Afs*10), in the VPS13B gene, and thus the boy was diagnosed with Cohen syndrome. Cohen syndrome is a rare autosomal recessive disorder caused by the VPS13B gene mutations and has complex clinical manifestations. Its clinical features include microcephalus, unusual facies, neutropenia, and joint hyperextension. VPS13B gene detection helps to make a confirmed diagnosis.