Diet therapy and metabolic control among Chilean adults with a neonatal diagnosis of Phenylketonuria

Abstract Phenylketonuria (PKU) is an autosomal recessive defect affecting the metabolic pathway of phenylalanine (Phe), causing hyperphenylalaninemia and neurotoxicity. Diagnosis must occur in the neonatal period and treatment should begin as early as possible. Evidence implies that treatment adherence declines as age advances. The aim was to describe the diet of a subgroup of Chilean adults with PKU currently in follow-up. Fifty-three subjects (49% women) followed up between January 2021 to April 2023 were considered. The concentration of Phe (PheC) in dried blood spots measured by fluorometry and 24-hour dietary recalls were analyzed. The median PheC of the sample was 438µmol/L (interquartile range(IQR):351-585µmol/L). A protein intake of 1.35±0.3 gr/Kg/d was observed of which 87% came from the protein substitute without Phe. Participants had a median Phe intake of 459mg/d (IQR:327-976) and 13.1g/d of fiber intake. Most participants, 51% and 92% reported consuming fruits and vegetables, respectively, and 32% consumed Low-Protein foods. Regarding micronutrients, all participants exceeded 90% adequacy according to recommendations. For vitamin-D and vitamin-B12, 100% is provided by the protein substitute. According to our results, it is mandatory to establish transition programs toward adulthood, to constantly maintain good metabolic control, and to adapt diet therapy to their new lifestyle.

Uso de bebidas energizantes y síntomas de insomnio en estudiantes de medicina de una universidad peruana / Use of energy drinks and insomnia symptoms in medical students from a Peruvian university

OBJETIVO: Determinar la asociación entre el consumo de bebidas energizantes y síntomas de insomnio en estudiantes de medicina de una universidad en Lima, Perú. MATERIALES Y MÉTODO: El tipo de estudio realizado es transversal analítico. La población objetivo fueron los estudiantes de medicina de una universidad peruana ubicada en Lima sur de segundo y quinto año. Hubo 289 participantes en el estudio. Se utilizó una encuesta compuesta por un cuestionario sobre el consumo de bebidas energizantes y el Insomnia Severity Index, del cual se determinó un punto de corte de 15 para considerar la presencia de síntomas de insomnio. El análisis multivariado crudo y ajustado se realizó usando la regresión de Poisson con varianza robusta ajustado para sexo, edad, consumo de café, y antecedente de ansiedad y depresión, para obtener el PR (Razón de Prevalencias) con un intervalo de confianza de 95%. RESULTADOS Y DISCUSIÓN: La prevalencia de síntomas de insomnio en la muestra estudiada fue de 21,80%, mientras que la de consumo de bebidas energizantes fue de 39,45%. Se encontró asociación significativa (p=0,008) entre el consumo de este tipo de bebidas y la presencia de síntomas de insomnio. Además, se encontró que los estudiantes que consumen bebidas energizantes tuvieron 1,78 veces más probabilidad de presentar síntomas de insomnio (IC95%: 1,13-2,82), en comparación con los que no consumieron bebidas energizantes (p=0,013). CONCLUSIONES: Existe asociación entre el consumo de bebidas energizantes y síntomas de insomnio.

OBJECTIVE: To determine the association between the consumption of energy drinks and symptoms of insomnia in medical students of a university in Lima, Peru. Materials and METHODS: This study is cross-sectional analytical. The target population was the second-and fifth-year medical students of a private Peruvian university in southern Lima. There were 289 participants in this study. For this study, a survey composed of a questionnaire about the consumption of energy drinks and the Insomnia Severity Index were used, from which a cut-off point of 15 was determined to consider the presence of insomnia symptoms. The multivariate crude and adjusted analysis were done with Poisson regression with robust variance adjusted for sex, age, coffee consumption, previous diagnosis of depression and previous diagnosis of anxiety; to calculate the PR (Prevalence Ratio) with a 95% CI. RESULTS AND DISCUSSION: The prevalence of insomnia symptoms in the sample studied was 21,80%, while the consumption of energy drinks was 39,45%. A significant association was found (p = 0.008) between the consumption of this type of drinks and the presence of insomnia symptoms. In addition, it was found that students who consumed energy drinks were 1,78 times more likely to have symptoms of insomnia (95% CI: 1,13-2,82), compared to those who did not consume energy drinks (p=<0,013). CONCLUSIONS: There is an association between the consumption of energy drinks and symptoms of insomnia.

Molecular basis of various forms of maple syrup urine disease in Chilean patients.

BACKGROUND: Maple syrup urine disease (MSUD) is an autosomal recessive inherited metabolic disorder caused by the deficient activity of the branched-chain α-keto acid dehydrogenase (BCKD) enzymatic complex. BCKD is a mitochondrial complex encoded by four genes: BCKDHA, BCKDHB, DBT, and DLD. MSUD is predominantly caused by mutations in the BCKDHA, BCKDHB, and DBT genes which encode the E1α, E1ß, and E2 subunits of the BCKD complex, respectively. The aim of this study was to characterize the genetic basis of MSUD in a cohort of Chilean MSUD patients by identifying point mutations in the BCKDHA, BCKDHB, and DBT genes and to describe their impact on the phenotypic heterogeneity of these patients. METHODS: This manuscript describes a cross-sectional study of 18 MSUD patients carried out using PCR and DNA sequencing. RESULTS: Four novel pathogenic mutations were identified: one in BCKDHA (p.Thr338Ile), two in BCKDHB (p.Gly336Ser e p.Pro240Thr), and one in DBT (p.Gly406Asp). Four additional pathogenic mutations found in this study have been described previously. There were no correlations between the genotype and phenotype of the patients. CONCLUSION: If MSUD is diagnosed earlier, with a newborn screening approach, it might be possible to establish genotype-phenotype relationships more efficiently.

25 Hydroxy Vitamin D Level, Bone Health, Vitamin D and Calcium Intake in Chilean Patients with Phenylketonuria and Hyperphenylalaninemias

Abstract It has been shown that there is a decrease in the concentrations of 25 hydroxyvitamin D (25-OHD) and bone mineral density (BMD) in patients with phenylketonuria (PKU) in their follow-up. Our objective was to determine concentrations of 25-OHD in subjects with PKU and hyperphenylalaninemia (HPA). Transversal analytical study considered three groups: G1-PKU with neonatal diagnosis and formula intake without Phe; G2-HPA, without specific treatment and G3-C control group. Sixteen patients per group (aged 6-23) were included. Levels of 25-OHD, lumbar spine (L2-L4), femur and total BMD, intact parathormone (PTH) and vitamin D (VitD) and calcium intake were calculated. The Kruskal-Wallis statistical test was applied (p-value<0,05). Significant differences were detected in concentrations of 25-OHD between G1-PKU and G2-HPA (38.9 ng/mL; 28 ng/mL, respectively) (NV: >30 ng/mL). G1-PKU had a higher intake of VitD, with differences among groups. There were no significant differences among groups in relation to BMD and intact PTH. In conclusion, G1-PKU under treatment and with good adherence, does not present VitD deficiency and no BMD alterations are observed. In contrast, G2-HPA had a lower intake of VitD and decreased 25-OHD concentrations which could affect the bone architecture in the long term. Further studies on the G2-HPA are suggested.

Update on Dietary Compliance, Nutritional Status, and Neuropsychological Functioning in the Chilean Phenylketonuria cohort

Abstract Since 1992, Chile has had a Newborn Screening Program for Phenylketonuria (PKU), which currently has an incidence of 1:18,916 newborns. The objective of the current study was to describe the 2020 follow up of the Chilean PKU cohort. The variables analyzed were: nutritional status, dietary compliance and neuropsychological functioning. We conducted a descriptive cross-sectional statistical analysis. The 271 subjects with PKU had an average age of diagnosis of 17±8 days and a phenylalanine (Phe) level of 1122±546 umol/L. Approximately 80% of protein requirement came from a protein substitute. For those <18 years of age, 80% had good dietary compliance with Phe level between 120-360 umol/L and those >18 years had a median of 522 umol/L (95%CI 468 - 636). Forty-four percent of the active PKU cohort had overweight/obesity. Eighty-five percent of the cohort >4 years of age had a normal intelligence quotient (IQ) (score 80-120). We observed a negative correlation (p <0.001; 95% CI: - 0.5, -0.2) between IQ score and Phe level. The Chilean protocol and protein substitute subsidy for life, together with the follow-up and continuous education carried out by the clinical team has encouraged compliance.

Characterization of Phenyalanine Hydroxylase Gene Mutations in Chilean PKU Patients.

Phenylketonuria (PKU, OMIM 261600) is an autosomal recessive disease, caused by mutations in the Phenylalanine Hydroxylase (PAH) gene situated in chromosome 12q22-q24.2. This gene has 13 exons. To date, 991 mutations have been described. The genotype is one of the main factors that determine the phenotype of this disease. OBJECTIVE: Characterize PKU genotype and phenotype seen in Chilean PKU patients. METHODS: We studied the PAH gene by restriction fragment length polymorphism (RFLP) and/or sequencing techniques to identify pathogenic mutations in 71 PKU subjects. We classified the phenotype according to Guldberg predicted value. RESULTS: We identified 26 different mutations in 134 of the 142 alleles studied (94.4%), 88.7% of the subjects had biallelic pathogenic mutations while 11.3% had only one pathogenic mutation identified. Compound heterozygous represented 85.9% of the cases. Exon 7 included the majority of mutations (26.9%) and 50% of mutations were missense. The most frequent mutations were c.1066-11G > A, c.442-?_509+?del and p.Val388Met. The majority of subjects (52.3%) had the classic phenotype. CONCLUSIONS: The most frequent mutations in our Chilean PKU population were p.Val388Met, c.442?_509+?del and c.1066-11G > A. It is possible to predict phenotype by detecting the genotype, and use this information to determine disease prognosis and adjust patient's medical and nutritional management accordingly.

Past, present and future of newborn screening in Chile.

The history of the Newborn Screening Program in Chile begins in 1984, when a pilot plan was developed that demonstrated the feasibility of its implementation. In 1992, the Ministry of Health started a national newborn screening program for phenylketonuria (PKU) and congenital hypothyroidism (CH), and in 1998, this was extended to the entire country. Throughout this period, a total of 2,478,123 newborns (NB) have been analyzed, obtaining initial coverage of 48.8%, which was later increased to 87.7%, and at present it is at 98.7% of all NB of our country. During this period, 131 cases with PKU have been diagnosed, resulting in an incidence of 1:18,916 NB, an average age of diagnosis of 18 ± 10.2 days and average phenylalanine level of 19,9 ± 8.8 mg/dl. In relation to CH, 783 cases have been confirmed, arriving at an incidence of 1:3,163 NB, with average age of diagnosis of 12.5 ± 6.9 days. Due to the good results of the program, the government is evaluating the initiation of an extended pilot program, to introduce other pathologies.

Methylmalonic acidaemia: examination of genotype and biochemical data in 32 patients belonging to mut, cblA or cblB complementation group.

Methylmalonic acidaemia (MMA) is a genetic disorder caused by defects in methylmalonyl-CoA mutase or in any of the different proteins involved in the synthesis of adenosylcobalamin. The aim of this work was to examine the biochemical and clinical phenotype of 32 MMA patients according to their genotype, and to study the mutant mRNA stability by real-time PCR analysis. Using cellular and biochemical methods, we classified our patient cohort as having the MMA forms mut (n = 19), cblA (n = 9) and cblB (n = 4). All the mut (0) and some of the cblB patients had the most severe clinical and biochemical manifestations, displaying non-inducible propionate incorporation in the presence of hydroxocobalamin (OHCbl) in vitro and high plasma odd-numbered long-chain fatty acid (OLCFA) concentrations under dietary therapy. In contrast, mut (-) and cblA patients exhibited a milder phenotype with propionate incorporation enhanced by OHCbl and normal OLCFA levels under dietary therapy. No missense mutations identified in the MUT gene, including mut (0) and mut (-) changes, affected mRNA stability. A new sequence variation (c.562G>C) in the MMAA gene was identified. Most of the cblA patients carried premature termination codons (PTC) in both alleles. Interestingly, the transcripts containing the PTC mutations were insensitive to nonsense-mediated decay (NMD).

Enzymatic and morphological evaluation of the hepatic cytoprotective effect of somatostatin and octreotide during extended experimental liver preservation.

Cytoprotective effects on the liver of somatostatin (ST) and octreotide (OT) have been previously described in normothermic ischemia-reperfusion models. The purpose of this study was an enzymatic and morphological assessment of hepatic cytoprotective effects during extended cold storage. Rat livers were washed in situ via the portal vein with University of Wisconsin solution (UW) UW+ST, or UW+OT. After 24 or 48 hours of cold ischemia time (CIT), livers were reperfused for 2 hours via the portal vein with oxygenated KHB at 37 degrees C using a nonrecirculating ex situ isolated perfusion system. Levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and creatinine kinase (CK) were assessed in the perfusate during ex situ isolated reperfusion. After a 24-hour cold ischemia time (CIT) ALT, LDH, and CK levels were significantly lower (P < .05) in the UW+ST and the UW+OT livers than the UW livers. After 48-hour CIT, AST, ALT, LDH, and CK levels were significantly lower (P < .05) in the UW+ST and the UW+OT livers than the UW livers. Histopathological examination revealed mild differences after 24-hour CIT but an evidently less ischemically damage organ after 48-hour CIT. With the limitations of an in vitro model, ST and OT showed enzymatic and morphological effects during extended liver preservation.

Electrical impedance of the liver during experimental long-term liver preservation.

Measurements of electrical impedance were performed to assess ischemic damage in the rabbit liver during long-term preservation with University of Wisconsin (UW) or histidine-tryptophan-ketoglutarate (HTK) solution. The impedance was measured at a frequency of 200 Hz after in situ perfusion and after cold storage for 24 and 48 hours in UW or HTK solution (six livers per group). Z(200 Hz) was significantly higher (P < .01) after 48 compared with 24 hours of cold storage with both protection solutions without significant differences between the livers preserved with both solutions. Electrical impedance was observed to be a sensitive indicator of liver damage during long-term protection, showing similar preservation quality for both preservation solutions.

Cystic mature teratoma of the filum terminale in an adult. Case report and review of the literature.

Intradural spinal teratoma is a very rare entity, more prevalent in childhood, that may associate with dysraphic defects. The authors report a 46 years old man with a cauda equina syndrome and an L1-2 tumor. An L1-2 laminectomy was performed and a mass was resected at the base of the filum terminale, which was in contact with the conus medullaris. Histopathological diagnosis was of cystic mature teratoma. Spinal teratomas may be found anywhere along the spine, but are more frequent in the cauda equina. We discuss the origin of these tumors and review the literature concerning these lesions.

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Inflammatory C2-3 subluxation: a Grisel's syndrome variant.

The concurrence of non-traumatic atlanto-axial subluxation with inflammation of the adjacent neck tissues is known as Grisel's syndrome. We report a 5 year old boy with recurring episodes of head tilt and painful and restricted neck movements that developed after repeated bouts of sinusitis. Radiographs showed a subluxation of the C2-3 joint. Medical treatment, with cervical collar, physiotherapy, and non-steroid anti-inflammatory agents, led to complete cure of the disease. We suggest that Grisel's syndrome can occur in a location different from the classic atlanto-axial joint. To the best of our knowledge, this is the first report of a symptomatic case of Grisel's syndrome occurring at the C2-3 segment.

Atlanto-axial rotatory subluxation in children: early management.

Atlanto-axial rotatory subluxation (AARS) is an uncommon condition involving dislocation and abnormal fixation of the atlas on the axis. AARS is difficult to diagnose and if improperly treated it may lead to permanent neck deformity. We report a retrospective series of patients diagnosed with AARS seen during the last five years. The children presented with neck pain, head tilt, and reduction in neck mobility. In three of the cases the condition was secondary to cervical trauma and in the fourth it was associated with otitis (Grisel syndrome). The diagnosis was established by three-dimensional computerised tomography. In three cases, the atlanto-axial fixation was cured after cervical immobilisation and physiotherapy. A posterior cervical fusion was required in the remaining case. Early detection and intensive conservative treatment constitutes the mainstay of management of AARS. Surgery is reserved for cases with irreducible or recurrent subluxation.

Del Xq23 in a mosaic Turner female: molecular and cytogenetic studies.

We report a Turner patient aged 22 years with a 45,X/46,X,del(X)(q23) karyotype. Late replication studies showed preferential inactivation of the deleted X chromosome; FISH studies with a probe for total human telomeres showed hybridisation signal in the telomeres on both the normal and the deleted X chromosomes. Microsatellite analysis in the proposita and her family permitted us to conclude to the maternal origin of the deleted X chromosome, and to detect using the marker DXS1106 (Xq22) a probable meiotic recombination event above the breakage point suggesting that the deletion occurred underneath this point. The mild Turner stigmata may be explained by the 45,X cell line, and the gonadal dysgenesis probably by a partial deletion of the gonadal dysgenesis region Xq13-q23 (excluding Xq22).

Molecular characterization of phenylalanine hydroxylase deficiency in Chile. Mutations in brief no. 243. Online.

Both the haplotype distribution and the mutational spectrum of the phenylalanine hydroxylase (PAH) gene has been defined for the Chilean phenylketonuria (PKU) population. Mutation analysis was performed using a combined approach of screening for common European and Oriental mutations and application of the DGGE scanning method in the remaining uncharacterized alleles. A total of 16 different mutations have been identified, including two novel ones, Q232X and IVS11nt5. The most frequent mutations were IVS10nt-11 and V388M present both in the 13% of the mutant chromosomes. The rest of the mutations are rare. The haplotype association including VNTR and STR alleles, was examined to investigated the origin and distribution of PAH alleles in Chile. Our results are consistent with Southern Europeans as the major source of PAH mutations in Latin America. However, we have also detected mutations from East and Central Europe, such IVS12nt1, R408W and R252W. It is clear that the PKU mutation present in each Latin American country varies with the demographic profile and specific mutation scanning is necessary in each population both for diagnostic and prognostic purposes. The correlation between the genotypes and the phenotypes is consistent with the emerging pattern of mutation severity deduced from previous studies in related populations.