ABSTRACT
In this case study, we report the case of a 13-year-old girl with citrullinemia type 1 (MIM #215700), an autosomal recessive inherited disorder of the urea cycle, which was confirmed by the identification of a homozygous pathogenic variant in the argininosuccinate synthetase 1 (ASS1) gene. However, the patient presented abnormal hyperkinetic movements with global developmental delay and clinical signs that were not fully consistent with those of citrullinemia type 1 or with those of her siblings with isolated citrullinemia type 1. Exome sequencing showed the presence of a de novo heterozygous pathogenic variant in the adenylate cyclase type 5 (ADCY5) gene. The variant confirmed the overlap with the so-called ADCY5-related dyskinesia with orofacial involvement, which is autosomal dominant (MIM #606703), a disorder disrupting the enzymatic conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP). In addition to the citrullinemia-related low-protein diet and arginine supplementation, the identification of this second disease led to the introduction of a treatment with caffeine, which considerably improved the dyskinesia neurological picture. In conclusion, this case highlights the importance of clinical-biological confrontation for the interpretation of genetic variants, as one hereditary metabolic disease may hide another with therapeutic consequences. Summary: This article reports the misleading superposition of two inherited metabolic diseases, showing the importance of clinical-biological confrontation in the interpretation of genetic variants.
ABSTRACT
Obinutuzumab (GA101) is a humanized anti-CD20 monoclonal antibody used in the treatment of B-cell malignancies. Under rare occasions, obinutuzumab may induce acute and severe thrombocytopenia. However, little is known about this side effect, referred to as "obinutuzumab-induced acute thrombocytopenia" (OIAT). Here, we report 2 cases of OIAT and review the literature to inform the management and outcome of this rare but life-threatening complication. The first case is a 74 year- old woman who was treated with obinutuzumab-Cyclophosphamide, Vincristine, Prednisone (CVP) for a previously untreated follicular lymphoma. This patient experienced an acute thrombocytopenia with a drop in her platelet count from 376 G/L to 3 G/L the day after treatment. The second case is a 44 year- old woman who was treated with obinutuzumab as a pre-treatment dose (day-8) before glofitamab infusion as a 4th line therapy for mantle cell lymphoma. This patient experienced an acute thrombocytopenia with a drop in her platelet count from 76 G/L (due to splenomegaly and bone marrow involvement) to 3 G/L the day after treatment. OIAT is a rare but life-threatening complication. Physicians should be aware of this adverse event to optimally detect and treat this complication.
