Clinical experience with hepatorenal tyrosinemia from a single Egyptian center

Abstract

Although very recently, in Egypt, sick newborn screening has included screening for hepatorenal tyrosinemia, yet, it is not yet included in nationwide neonatal screening and hence diagnosis may be delayed. The aim of this study was to analyze data of all cases presenting with hepatorenal tyrosinemia to the Pediatric Hepatology Unit, Cairo University, Egypt from 2006 to 2019. Data were retrieved from patients’ files including age of onset of symptoms, clinical signs, blood counts, liver functions, serum phosphorous, alpha-fetoprotein, succinylacetone and abdominal ultrasound. During this period, 76 patients were diagnosed with hepatorenal tyrosinemia if succinylacetone in dry blood spot was elevated above 1 μmol/L. These 76 cases came from 70 families; consanguinity was reported in 61 families. In our cohort we reported 30 affected siblings with a similar clinical presentation, who died undiagnosed. Presentation was acute in 26%, subacute in 30% and chronic in 43%. Abdominal distention was the commonest presenting symptom (52.6%). Coagulopathy was the commonest derangement in liver functions; hyperbilirubinemia and raised transaminases were less common. Ultrasound findings included hepatic focal lesions in 47% and enlarged echogenic kidneys in 39% and 45.3% respectively. Only 20 children were treated with Nitisinone because of unavailability and high costs; seven out of them underwent liver transplantation. In conclusion, although hepatorenal tyrosinemia is a rare inborn error of metabolism, in a large population country with high rate of consanguinity; this disease is not uncommonly diagnosed. The current treatment is not readily available because of the costs in a resource-limited country. Neonatal screening and subsidization of the costly medication need to be considered.

Role of Alpha-Fetoprotein (AFP) in Diagnosing Childhood Cancers and Genetic-Related Chronic Diseases

“…Long-term administration of nitisinone (2-(2-nitro-4-3 trifluoromethylbenzoyl)-1,3-cyclohexanedione-NTBC), a well-established therapy for patients with type I tyrosinemia, is recommended. NTBC reduces the risk of HCC and porphyria attacks and leads to a decrease in AFP levels [19,20]. However, Bhushan et al observed in their patient cases that even with long-term NTBC therapy and normalization of AFP, the risk of HCC is not completely eliminated [16,21].…”

“…Studies have shown that other bone marrow disorders with a genetic basis, such as Blackfan-Diamond syndrome, Shwachman-Diamond anemia, or congenital dyskeratosis congenital, exhibit normal AFP levels [36]. Until recently, AFP was used as a simple diagnostic tool for Fanconi anemia (FA), with studies indicating varied sensitivity: 93% sensitivity and 100% specificity (Cassinat et al, 2000) [37]; 46% sensitivity (Aslan et al, 2002) [19]; and 71% sensitivity (Salem et al, 2019) [17]. However, a recent study by Alter et al suggests a sensitivity of approximately 25%, although their study included a group of FA patients with a higher median age [36].…”