RESUMEN
We report the first case of blood chimerism involving a pathogenic RB1 variant in naturally conceived monochorionic-dizygotic twins (MC/DZ) with the twin-twin-transfusion syndrome (TTTS), presumably caused by the exchange of stem-cells. Twin A developed bilateral retinoblastoma at 7 months of age. Initial genetic testing identified a de novo RB1 pathogenic variant, with a 20% allelic ratio in both twins' blood. Subsequent genotyping of blood and skin confirmed dizygosity, with the affected twin harboring the RB1 pathogenic variant in skin and blood, and the unaffected twin carrying the variant only in blood.
Asunto(s)
Transfusión Feto-Fetal/sangre , Proteína de Retinoblastoma/genética , Retinoblastoma/sangre , Gemelos Dicigóticos/genética , Quimerismo , Femenino , Transfusión Feto-Fetal/genética , Transfusión Feto-Fetal/patología , Humanos , Lactante , Embarazo , Embarazo Gemelar/sangre , Embarazo Gemelar/genética , Retinoblastoma/genética , Retinoblastoma/patología , Proteína de Retinoblastoma/sangre , Células Madre/metabolismo , Células Madre/patología , Gemelos Monocigóticos/genética , Ultrasonografía PrenatalRESUMEN
Nirmatrelvir/ritonavir was recently granted emergency use authorization for mild to moderate coronavirus disease 2019. Drug-drug interactions between ritonavir and tacrolimus are underappreciated by nontransplant providers. We describe 2 solid organ transplant recipients prescribed nirmatrelvir/ritonavir for outpatient use who developed tacrolimus toxicity requiring hospitalization and were managed with rifampin for toxicity reversal.