Cushing Syndrome in a Pediatric Patient With a KCNJ5 Variant and Successful Treatment With Low-dose Ketoconazole

[nighthawk]

From the abstract (appearing in JCEM Feb 2021):

PATIENT

We present the case of a 10-year-old child who presented with CS at an early age due to bilateral adrenocortical hyperplasia (BAH). The patient was placed on low-dose ketoconazole (KZL), which controlled hypercortisolemia and CS-related signs. Discontinuation of KZL for even 6 weeks led to recurrent CS.

CONCLUSIONS

We present a pediatric patient with CS due to BAH and a germline defect in KCNJ5. Molecular investigations of this KCNJ5 variant failed to show a definite cause of her CS. However, this KCNJ5 variant differed in its function from KCNJ5 defects leading to PA. We speculate that GIRK4 (Kir3.4) may play a role in early human adrenocortical development and zonation and participate in the pathogenesis of pediatric BAH.

Official: Cushing Syndrome in a Pediatric Patient With a KCNJ5 Variant and Successful Treatment With Low-dose Ketoconazole

Pre-print (pdf): https://www.researchgate.net/publication/349635365_Cushing_Syndrome_in_a_Pediatric_Patient_With_a_KCNJ5_Variant_and_Successful_Treatment_With_Low-dose_Ketoconazole

 

 

[nighthawk]

Posted because it's interesting for a few reasons, especially the fact that this apparent adrenal Cushing's (bilateral micronodular hyperplasia) did not present with suppressed ACTH. Those values ranged from 8.9 to 38 pg/mL throughout the day, and yet this was not a mild case biochemically. The investigators--who I should point out are the leading experts on this particular subtype of Cushing's--seemed baffled by the discordant results for locating the source. Furthermore, this novel mutation has a different proposed mechanism of action than previously-identified mutations. Finally, the rather young pediatric patient has been successfully treated with low-dose ketoconazole for five years.