False Negative ^99mTc-DPD Scintigraphy in pVal50Met(Val30Met) Hereditary Transthyretin Amyloidosis

Hereditary ATTR amyloidosis (hATTR) is a rare genetic disorder with autosomal dominant transmission, resulting from a point mutation in the transthyretin (TTR) gene. Symptoms are related to the deposition of TTR fibrils (amyloid deposits) in various tissues, including peripheral nerves and the heart. Cardiac symptoms include myocardial hypertrophy and conduction disorders. Among the more than 100 recognized TTR mutations, the pVal50Met (Val30Met) variant is the most prevalent worldwide with early onset of the disease. Assessment of cardiac amyloid infiltration primarily relies on cardiac imaging including echocardiography, cardiac magnetic resonance and 99mTcPYP/DPD/HMDP scintigraphy. Scintigraphy is reported as particularly sensitive, allowing early diagnosis.1