Biomarkers of Micronutrients in Regular Follow-Up for Tyrosinemia Type 1 and Phenylketonuria Patients

Abstract

Phenylketonuria (PKU) is treated with dietary restrictions and sometimes tetrahydrobiopterin (BH4). PKU patients are at risk for developing micronutrient deficiencies, such as vitamin B12 and folic acid, likely due to their diet. Tyrosinemia type 1 (TT1) is similar to PKU in both pathogenesis and treatment. TT1 patients follow a similar diet, but nutritional deficiencies have not been investigated yet. In this retrospective study, biomarkers of micronutrients in TT1 and PKU patients were investigated and outcomes were correlated to dietary intake and anthropometric measurements from regular follow-up measurements from patients attending the outpatient clinic. Data was analyzed using Kruskal–Wallis, Fisher’s exact and Spearman correlation tests. Furthermore, descriptive data were used. Overall, similar results for TT1 and PKU patients (with and without BH4) were observed. In all groups high vitamin B12 concentrations were seen rather than B12 deficiencies. Furthermore, all groups showed biochemical evidence of vitamin D deficiency. This study shows that micronutrients in TT1 and PKU patients are similar and often within the normal ranges and that vitamin D concentrations could be optimized.

Bone Status in Patients with Phenylketonuria: A Systematic Review

“…PKU patients are detected early by newborn screening, put in place in the 1960s, and are treated predominantly using a Phe-restricted diet, which limits the intake of natural protein. As the first early treated PKU patients age, concerns have arisen about the long-term consequences of PKU and its treatment [ 10 , 11 , 12 , 13 , 14 ], including deleterious effects on bone health [ 15 , 16 ]. Osteoporosis is a silent disease until it is complicated by fractures that can occur due to minimal or no trauma.…”

“…More recently, enzyme substitution therapy has been approved to treat PKU in patients aged 16 years or older [ 9 ]. The success of treatment has, however, led to the discovery of secondary issues in the life-long outcome of PKU patients, including nutritional deficiencies in minerals, vitamins, and long chain polyunsaturated fatty acids [ 10 , 11 , 12 , 13 ], behavioral impairment [ 13 , 14 ], and mineral bone disease [ 15 , 16 ]. Such micronutrient nutritional deficiencies will be highly dependent on the compliance to the treatment.…”

Protein status in phenylketonuria: A scoping review

“…A range of biochemical measurements were used to assess protein status, and most studies included multiple measurement (Table 3). Serum albumin [36,41,42,56,62,63,69,72,74,78,85,86,95], prealbumin [26,34,37,57,80,81,84,87,89] or both [33,38,40,45,46,76,77,82,83,88,90,91,93,94] were the most common biochemical measurements reported. Total protein [36,40e42,56,63,72,76,78,80,81,85,86,91,93,94] and blood urine nitrogen (BUN) [33,40,45,74,75,78,85,86,93] were also frequently used.…”

Malnutrition in Pediatric Chronic Cholestatic Disease: An Up-to-Date Overview

“…The clinical manifestations vary and include neonatal cholestasis with acute liver failure, hepatocellular carcinoma, growth retardation, renal dysfunction, and porphyria-like syndrome with neuropathy [ 102 ]. The current specific treatment consists of 2-(2 nitro-4-3 trifluoro-methylbenzoyl)-1,3-cyclohexanedione (NTBC) paired with a tyrosine- and phenylalanine-restricted diet Many commercial products containing tyrosine- and phenylalanine-free amino acid mixtures and supplemented with vitamins and minerals are available [ 103 ]. The aim of combined treatment (NTBC and diet) is to provide adequate nutrition that allows normal growth and development, keeping the tyrosine levels in the blood and tissues under control [ 104 ].…”