Updated, web-based nutrition management guideline for PKU: An evidence and consensus based approach.

BACKGROUND: In 2014, recommendations for the nutrition management of phenylalanine hydroxylase deficiency were published as a companion to the concurrently published American College of Medical Genetics and Genomics guideline for the medical treatment of phenylketonuria (PKU). These were developed primarily from a summary of findings from the PKU scientific review conference sponsored by the National Institutes of Health and Agency for Healthcare Research & Quality along with additional systematic literature review. Since that time, the Genetic Metabolic Dietitians International and the Southeast Regional Newborn Screening and Genetics Collaborative have partnered to create a web-based technology platform for the update and development of nutrition management guidelines for inherited metabolic disorders. OBJECTIVE: The purpose of this PKU guideline is to establish harmonization in treatment and monitoring, to guide the integration of nutrition therapy in the medical management of PKU, and to improve outcomes (nutritional, cognitive, and developmental) for individuals with PKU in all life stages while reducing associated medical, educational, and social costs. METHODS: Six research questions critical to PKU nutrition management were formulated to support guideline development: Review, critical appraisal, and abstraction of peer-reviewed studies and unpublished practice literature, along with expert Delphi survey feedback, nominal group process, and external review from metabolic physicians and dietitians were utilized for development of recommendations relevant to each question. Recommendations address nutrient intake, including updated protein requirements, optimal blood phenylalanine concentrations, nutrition interventions, monitoring parameters specific to life stages, adjunct therapies, and pregnancy and lactation. Recommendations were graded using a rigorous system derived from the Academy of Nutrition and Dietetics. RESULTS AND CONCLUSION: These guidelines, updated utilizing a thorough and systematic approach to literature analysis and national consensus process, are now easily accessible to the global community via the newly developed digital platform. For additional details on specific topics, readers are encouraged to review materials on the online portal: https://GMDI.org/.

Pilot study to evaluate the effects of tetrahydrobiopterin on adult individuals with phenylketonuria with measurable maladaptive behaviors.

OBJECTIVES: To evaluate the effects of tetrahydrobiopterin (BH4) on maladaptive behavior in patients with phenylketonuria (PKU). METHODS: In an effort to determine if BH4 has any effects on the central nervous system, we studied 10 individuals with PKU and measurable maladaptive behaviors for 1 year. Behavioral assessments using the Vineland Adaptive Behavior Scales-Second Edition and a PKU Behavior Checklist were obtained at baseline, 6 months, and at the end of the study. Biochemical measures including plasma amino acids were obtained quarterly, and phenylalanine (Phe) and tyrosine (Tyr) were obtained monthly. RESULTS: Out of the 10 subjects, 2 were responders to BH4, as determined by a blood Phe reduction >30%. While blood Phe in the 8 nonresponders did not change significantly throughout the study, their Tyr levels were significantly higher at 6 months (p=0.012), but not at 12 months (p=0.23). By the end of the study, 8 subjects exhibited fewer maladaptive behaviors on the components of the Vineland Maladaptive Behavior Index, and all 10 had lower total scores on the PKU Behavior Checklist. CONCLUSION: These findings suggest that there may be direct effects of BH4 on the central nervous system, independent of lowering blood Phe.

Recommendations for the nutrition management of phenylalanine hydroxylase deficiency.

The effectiveness of a phenylalanine-restricted diet to improve the outcome of individuals with phenylalanine hydroxylase deficiency (OMIM no. 261600) has been recognized since the first patients were treated 60 years ago. However, the treatment regime is complex, costly, and often difficult to maintain for the long term. Improvements and refinements in the diet for phenylalanine hydroxylase deficiency have been made over the years, and adjunctive therapies have proven to be successful for certain patients. Yet evidence-based guidelines for managing phenylalanine hydroxylase deficiency, optimizing outcomes, and addressing all available therapies are lacking. Thus, recommendations for nutrition management were developed using evidence from peer-reviewed publications, gray literature, and consensus surveys. The areas investigated included choice of appropriate medical foods, integration of adjunctive therapies, treatment during pregnancy, monitoring of nutritional and clinical markers, prevention of nutrient deficiencies, providing of access to care, and compliance strategies. This process has not only provided assessment and refinement of current nutrition management and monitoring recommendations but also charted a direction for future studies. This document serves as a companion to the concurrently published American College of Medical Genetics and Genomics guideline for the medical treatment of phenylalanine hydroxylase deficiency.

Phenylketonuria Scientific Review Conference: state of the science and future research needs.

New developments in the treatment and management of phenylketonuria (PKU) as well as advances in molecular testing have emerged since the National Institutes of Health 2000 PKU Consensus Statement was released. An NIH State-of-the-Science Conference was convened in 2012 to address new findings, particularly the use of the medication sapropterin to treat some individuals with PKU, and to develop a research agenda. Prior to the 2012 conference, five working groups of experts and public members met over a 1-year period. The working groups addressed the following: long-term outcomes and management across the lifespan; PKU and pregnancy; diet control and management; pharmacologic interventions; and molecular testing, new technologies, and epidemiologic considerations. In a parallel and independent activity, an Evidence-based Practice Center supported by the Agency for Healthcare Research and Quality conducted a systematic review of adjuvant treatments for PKU; its conclusions were presented at the conference. The conference included the findings of the working groups, panel discussions from industry and international perspectives, and presentations on topics such as emerging treatments for PKU, transitioning to adult care, and the U.S. Food and Drug Administration regulatory perspective. Over 85 experts participated in the conference through information gathering and/or as presenters during the conference, and they reached several important conclusions. The most serious neurological impairments in PKU are preventable with current dietary treatment approaches. However, a variety of more subtle physical, cognitive, and behavioral consequences of even well-controlled PKU are now recognized. The best outcomes in maternal PKU occur when blood phenylalanine (Phe) concentrations are maintained between 120 and 360 µmol/L before and during pregnancy. The dietary management treatment goal for individuals with PKU is a blood Phe concentration between 120 and 360 µmol/L. The use of genotype information in the newborn period may yield valuable insights about the severity of the condition for infants diagnosed before maximal Phe levels are achieved. While emerging and established genotype-phenotype correlations may transform our understanding of PKU, establishing correlations with intellectual outcomes is more challenging. Regarding the use of sapropterin in PKU, there are significant gaps in predicting response to treatment; at least half of those with PKU will have either minimal or no response. A coordinated approach to PKU treatment improves long-term outcomes for those with PKU and facilitates the conduct of research to improve diagnosis and treatment. New drugs that are safe, efficacious, and impact a larger proportion of individuals with PKU are needed. However, it is imperative that treatment guidelines and the decision processes for determining access to treatments be tied to a solid evidence base with rigorous standards for robust and consistent data collection. The process that preceded the PKU State-of-the-Science Conference, the conference itself, and the identification of a research agenda have facilitated the development of clinical practice guidelines by professional organizations and serve as a model for other inborn errors of metabolism.

Melatonin and dopamine as biomarkers to optimize treatment in phenylketonuria: effects of tryptophan and tyrosine supplementation.

OBJECTIVE: To determine whether additional supplementation of tryptophan (Trp) and tyrosine (Tyr) improve serotonin and dopamine metabolism in individuals with phenylketonuria treated with large neutral amino acid (LNAA) tablets. STUDY DESIGN: Ten adult individuals with phenylketonuria participated in a randomized, double-blind, placebo-controlled cross-over study consisting of three 3-week phases: washout, treatment with LNAA tablets plus supplementation with either Trp and Tyr tablets or placebo, and LNAA tablets plus the alternate supplementation. An overnight protocol to measure blood melatonin, a serotonin metabolite in the pinealocytes, and urine 6-sulfatoxymelatonin and dopamine in first-void urine specimens was conducted after each phase. RESULTS: Serum melatonin and urine 6-sulfatoxymelatonin and dopamine levels were increased in the LNAA phase (LNAA plus placebo) compared with the washout phase. Serum melatonin and urine 6-sulfatoxymelatonin were not increased in the active phase (LNAA plus Trp + Tyr) compared with the LNAA phase, although plasma Trp:LNAA was increased compared with the LNAA phase. Among 7 subjects with a plasma Trp/LNAA >0.03, a negative correlation between urine 6-sulfatoxymelatonin and plasma phenylalanine levels was observed (r = -0.072). Urine dopamine levels and plasma Tyr:LNAA were increased in the active phase compared with the LNAA phase. CONCLUSION: Melatonin levels were not increased with the higher dose of Trp supplementation, but dopamine levels were increased with the higher dose of Tyr supplementation. Serotonin synthesis appears to be suppressed by high phenylalanine levels at the Trp hydroxylase level.

Maternal Phenylketonuria International Collaborative Study revisited: evaluation of maternal nutritional risk factors besides phenylalanine for fetal congenital heart defects.

Maternal phenylketonuria (MPKU) is known to affect fetal outcome, often being associated with microcephaly and congenital heart defects (CHD) if the maternal diet is not appropriately managed. We hypothesized that other nutrients aside from phenylalanine (Phe) may have significant effects on fetal outcome in MPKU pregnancies. The 416 pregnancies that resulted in live births reported in the Maternal PKU Collaborative Study (MPKUCS) were grouped according to whether or not the offspring were diagnosed with CHD. The groups were compared on first-trimester values of maternal data, including weight gain, plasma amino acids, protein and Phe intake, and red blood cell (RBC) folate. Patients were also grouped by first-trimester average blood Phe (≤910 µmol/L and >910 µmol/L) and then divided by total natural protein and medical food intake. The CHD group of 28 offspring had significantly higher blood Phe and lower proline, valine, methionine, isoleucine, leucine, lysine, arginine, and RBC folate. A significantly higher risk for CHD was found in the groups with lower natural protein and medical food intake, regardless of blood Phe levels. Insufficient natural protein and medical food product intake appears to be a risk factor for CHD independent of first-trimester plasma Phe levels. Low RBC folate and plasma methionine levels in the CHD group may suggest involvement of global DNA hypomethylation.

Glycosaminoglycan metabolism defects and atherosclerosis: frequent association of endothelial dysfunction in patients with Mucopolysaccharidosis.

Cardiovascular lesions, including coronary artery stenosis, are frequently associated and can cause sudden death in patients with genetic defects of glycosaminoglycan (GAG) metabolism. Early diagnosis of coronary artery lesions is difficult, although potentially lifesaving. Histopathological similarities between atherosclerotic changes in adults and in patients with genetic GAG metabolism defects have been known. Atherosclerosis is the result of a complex process involving metabolism of GAGs and proteoglycans preceded by endothelial dysfunction as a key event. Decreased nitric oxide (NO) bioavailability is considered the hallmark of endothelial dysfunction. Reduced NO synthase (NOS) has been reported in atherosclerotic arteries. Impairment in reactive hyperemia-digital peripheral arterial tonometry (RH-PAT) with EndoPAT has been validated to correlate coronary microvascular function in patients with atherosclerosis. RH-PAT is thought to reflect endothelial NO production. Immunohistological staining of endothelial NOS was performed in the stenotic lesions in the coronary artery of a 3-year-old patient with Mucopolysaccharidosis-I, showing decreased activities. This prompted a study to measure endothelial function in patients with GAG metabolism defects for early diagnosis of endothelial dysfunction in the coronary arteries as an early sign of coronary artery changes. Evaluation by RH-PAT in 30 patients with variable genetic defects in GAG metabolism revealed significantly decreased Reactive Hyperemia Indexes compared with 12 controls. Evaluation of endothelial function with RH-PAT in patients with GAG metabolism defects may detect coronary artery lesions that can be underdiagnosed by the other measures such as coronary angiography. Use of this method may prove vital in the management of patients with GAG metabolism defects.

Newborn screening 50 years later: access issues faced by adults with PKU.

Fifty years after the implementation of universal newborn screening programs for phenylketonuria, the first disease identified through newborn screening and considered a success story of newborn screening, a cohort of adults with phenylketonuria treated from birth provides valuable information about effects of long-term treatment for inborn errors of metabolism in general, and phenylketonuria specifically. For phenylketonuria, newborn screening allows early implementation of the phenylalanine-restricted diet, eliminating the severe neurocognitive and neuromotor impairment associated with untreated phenylketonuria. However, executive function impairments and psychiatric problems are frequently reported even for those treated early and continuously with the phenylalanine-restricted diet alone. Moreover, a large percentage of adults with phenylketonuria are reported as lost to follow-up by metabolic clinics. While a group of experts identified by the National Institutes of Health convenes to update treatment guidelines for phenylketonuria, we explore individual patient, social, and economic factors preventing >70% of adult phenylketonuria patients in the United States from accessing treatment. As more conditions are identified through newborn screening, factors affecting access to treatment grow in importance, and we must continue to be vigilant in assessing and addressing factors that affect patient treatment outcomes and not just celebrate amelioration of the most severe manifestations of disease.

Large neutral amino acid supplementation increases melatonin synthesis in phenylketonuria: a new biomarker.

OBJECTIVE: To determine whether levels of melatonin in blood and urine can serve as a peripheral biomarker to reflect brain serotonin synthesis in individuals with phenylketonuria (PKU). STUDY DESIGN: We measured the levels of melatonin, a serotonin metabolite in the pinealocytes, in the blood and urine of individuals with PKU in a randomized double-blind placebo controlled crossover study consisting of three 3-week phases in 10 adults with PKU: phase 1 (washout), phase 2 (supplementation of large neutral amino acid [LNAA] tablets or placebo), and phase 3 (alternate supplementation). An overnight protocol to measure blood melatonin and urine 6-sulfatoxymelatonin and dopamine in first void urine specimens was conducted after each phase for subjects with PKU and once in 10 controls. RESULTS: Significantly lower concentrations of these neurotransmitter metabolites were observed in subjects with PKU after phase 1 compared with controls (serum melatonin P = .008, urine melatonin P = .0043, urine dopamine P < .0001), with significant increases after LNAA supplementation compared with the placebo phase (serum melatonin P = .0008, urine melatonin P = .0008, urine dopamine P = .0005). The mean tryptophan/LNAA and tyrosine/LNAA ratios were markedly lower in subjects with PKU compared with controls, and these ratios were significantly increased in the LNAA phase compared with the placebo phase (P = .016, P = .0003, respectively). Blood phenylalanine levels in subjects with PKU were not significantly different between placebo and LNAA phases (P = .74). CONCLUSION: Blood and urine melatonin levels may serve as biomarkers reflecting brain serotonin synthesis in subjects with PKU. Because this cannot be evaluated using blood phenylalanine levels, it may provide information on neurotransmitter metabolism for optimal dietary management.

Who counsels parents of newborns who are carriers of sickle cell anemia or cystic fibrosis?

Our objective was to describe: 1) physicians' knowledge of whether genetic counseling is provided to parents of newborns with sickle cell trait (SCT) or who are cystic fibrosis carriers (CFC), and 2) the prevalence of genetic counseling provided by primary care physicians. We conducted a cross-sectional descriptive survey of 600 randomly-sampled Michigan-based pediatricians and family physicians, assessing physician knowledge of where and whether genetic counseling is received by parents whose newborns are carriers. Chi-squared testing determined associations between genetic counseling location and physician demographic characteristics. Our response rate was 62 %: 298 (84 %) provided infant well care (183 pediatricians, 115 family physicians). Most respondents were non-Hispanic White (65 %). Virtually all physicians believed parents whose newborns are carriers of either SCT or CFC should receive some genetic counseling (from the physician and/or another source), yet 20 % reported that parents of newborns with SCT did not receive counseling. Parents of infants with CFC received more counseling overall (92 % vs. 80 %; p < 0.01) and were counseled more frequently by genetic counselors or specialty centers than parents of newborns with SCT (85 % vs. 60 %; p < 0.01). Although physicians agreed that parents whose newborns are carriers should receive genetic counseling, fewer parents of newborns with SCT than with CFC received counseling from any source. This finding strongly suggests the need for further education and investigation of this apparent health disparity.

Large Mesenteric Gaucheroma Responds to Substrate Reduction Therapy: A New Management of Gaucheromas.

Gaucheromas, which are pseudotumors consisting of a cluster of Gaucher cells, are rare complications in Gaucher's disease (GD) and reported in patients treated with enzyme replacement therapy (ERT). Gaucheromas commonly develop in the lymph nodes in the mesenteric and mediastinal regions and can cause serious complications including protein-losing enteropathy. A large mesenteric Gaucheroma showed a significant reduction in size after initiation of substrate reduction therapy (SRT) with eliglustat in an adult patient with GD type 3. Combination therapy with ERT and SRT should be considered to prevent Gaucheromas in patients with GD.

Steroid inhaler adherence, flu vaccine receipt, and race: associations with the quality of the parent-physician relationship for asthmatic children.

RATIONALE: Steroid inhaler adherence and influenza immunization rates are low for asthmatic minority children. OBJECTIVE: To examine associations between parents' adherence to administering their child's steroid inhaler, influenza vaccine receipt, and parental perceptions of the primary care experience. METHODS: In 2006 we interviewed parents of children aged 2-12 who had an asthma-related physician visit in 2004 and 2005 about steroid inhaler use and influenza vaccine receipt. Parents rated their child's doctor using the Primary Care Assessment Survey (PCAS). MEASUREMENT: Outcome variables were inhaler adherence and influenza vaccine receipt. Independent variables included PCAS scores, child health measures, parental personal and financial stress, and demographic variables. RESULTS: Children of inhaler-adherent parents were more likely to be immunized (OR, 2.94; p = .03). Black parents were less adherent to steroid use (OR, 0.37, p = .01) while nonblack/nonwhite children had lower vaccination rates (OR, 0.29, p = .02). Continuity of care was associated with better inhaler adherence (OR, 1.02, p = .01). Influenza immunization was associated with physician's knowledge of the child's medical history (OR, 1.02, p = .05), interpersonal skills (OR, 1.02, p = .03), and parental trust in the physician (OR, 1.03, p = .02). Minority parents gave lower ratings than white parents to their child's physician and office on characteristics associated with inhaler adherence and immunization. CONCLUSIONS: Minority parents of asthmatic children are less adherent to recommended asthma treatments and rate physicians lower on characteristics associated with adherence. Improving those characteristics may improve asthma outcomes for minority children.

Creating a segregated medical profession: African American physicians and organized medicine, 1846-1910.

An independent panel of experts, convened by the American Medical Association (AMA) Institute for Ethics, analyzed the roots of the racial divide within American medical organizations. In this, the first of a 2-part report, we describe 2 watershed moments that helped institutionalize the racial divide. The first occurred in the 1870s, when 2 medical societies from Washington, DC, sent rival delegations to the AMA's national meetings: an all-white delegation from a medical society that the US courts and Congress had formally censured for discriminating against black physicians; and an integrated delegation from a medical society led by physicians from Howard University. Through parliamentary maneuvers and variable enforcement of credentialing standards, the integrated delegation was twice excluded from the AMA's meetings, while the all-white society's delegations were admitted. AMA leaders then voted to devolve the power to select delegates to state societies, thereby accepting segregation in constituent societies and forcing African American physicians to create their own, separate organizations. A second watershed involved AMA-promoted educational reforms, including the 1910 Flexner report. Straightforwardly applied, the report's population-based criterion for determining the need for phySicians would have recommended increased training of African American physicians to serve the approximately 9 million African Americans in the segregated south. Instead, the report recommended closing all but 2 African American medical schools, helping to cement in place an African American educational system that was separate, unequal, and destined to be insufficient to the needs of African Americans nationwide.

Segregation, civil rights, and health disparities: the legacy of African American physicians and organized medicine, 1910-1968.

Between 1910 and 1968, the National Medical Association (NMA) repeatedly clashed with the American Medical Association (AMA) over the latter organization's racial bars to membership and other health policy issues. The NMA, founded in 1895 as a nonexclusionary medical society to provide a voice for disenfranchised black physicians and patients, struggled in its early years, during which AMA leadership took scant notice of it. But skirmishes ensued over such actions as stigmatizing racial labels in the AMA's American Medical Directory, which, beginning in 1906, listed all U.S. physicians but designated African Americans with the notation col. The NMA also repeatedly asked the AMA to take action against overt racial bars on blacks' membership in its constituent state and county societies. During the civil rights era, African American physicians received no AMA support in seeking legal remedies to hospital segregation. And the NMA and AMA found themselves opposed on other policy issues, including Medicaid and Medicare. These differences eventually catalyzed a series of direct confrontations. The 1965 AMA meeting in New York City, for example, was protested by about 200 NMA-led picketers. The NMA's quest for racial equality in medicine was supported by some other medical organizations, such as the Medical Committee for Human Rights. In 1966, the AMA House voted to amend the AMA Constitution and Bylaws, giving its Judicial Council (now the Council on Ethical and Judicial Affairs) the authority to investigate allegations of discrimination. This paved the way for a subsequent era of increasing cooperation and understanding.

Stereotyping across intersections of race and age: Racial stereotyping among White adults working with children.

This study examined the prevalence of racial/ethnic stereotypes among White adults who work or volunteer with children, and whether stereotyping of racial/ethnic groups varied towards different age groups. Participants were 1022 White adults who volunteer and/or work with children in the United States who completed a cross-sectional, online survey. Results indicate high proportions of adults who work or volunteer with children endorsed negative stereotypes towards Blacks and other ethnic minorities. Respondents were most likely to endorse negative stereotypes towards Blacks, and least likely towards Asians (relative to Whites). Moreover, endorsement of negative stereotypes by race was moderated by target age. Stereotypes were often lower towards young children but higher towards teens.

Correction: Stereotyping across intersections of race and age: Racial stereotyping among White adults working with children.

[This corrects the article DOI: 10.1371/journal.pone.0201696.].

Can untreated PKU patients escape from intellectual disability? A systematic review.

BACKGROUND: Phenylketonuria (PKU) is often considered as the classical example of a genetic disorder in which severe symptoms can nowadays successfully be prevented by early diagnosis and treatment. In contrast, untreated or late-treated PKU is known to result in severe intellectual disability, seizures, and behavioral disturbances. Rarely, however, untreated or late-diagnosed PKU patients with high plasma phenylalanine concentrations have been reported to escape from intellectual disability. The present study aimed to review published cases of such PKU patients. METHODS: To this purpose, we conducted a literature search in PubMed and EMBASE up to 8th of September 2017 to identify cases with 1) PKU diagnosis and start of treatment after 7 years of age; 2) untreated plasma phenylalanine concentrations ≥1200 µmol/l; and 3) IQ ≥80. Literature search, checking reference lists, selection of articles, and extraction of data were performed by two independent researchers. RESULTS: In total, we identified 59 published cases of patients with late-diagnosed PKU and unexpected favorable outcome who met the inclusion criteria. Although all investigated patients had intellectual functioning within the normal range, at least 19 showed other neurological, psychological, and/or behavioral symptoms. CONCLUSIONS: Based on the present findings, the classical symptomatology of untreated or late-treated PKU may need to be rewritten, not only in the sense that intellectual dysfunction is not obligatory, but also in the sense that intellectual functioning does not (re)present the full picture of brain damage due to high plasma phenylalanine concentrations. Further identification of such patients and additional analyses are necessary to better understand these differences between PKU patients.

Measuring African-American parents' cultural mistrust while in a healthcare setting: a pilot study.

BACKGROUND: African Americans' mistrust of healthcare is often cited as a cause of racial disparities in health and has been linked to cultural mistrust. African-American parents' level of cultural mistrust while in a general healthcare setting has not been previously measured. OBJECTIVE: To determine the performance, participant acceptance, feasibility of administration and demographic associations of a measure of cultural mistrust, the Cultural Mistrust Inventory (CMI), in African-American parents seeking healthcare. METHODS: A cross-sectional sample of 69 self-identified African-American parents of minor children recruited in a university-affiliated, urban pediatric/family practice outpatient clinic completed an anonymous, self-administered questionnaire containing demographic items and the CMI. RESULTS: The response rate was 91% (n=63), and 49 (78%) -- answered all questions. Measured mistrust did not vary with gender, insurance or education. The CMI's internal consistency was similar to previously published studies of the instrument (alpha=0.92). Parents indicating discomfort with the CMI's questions reported significantly less mistrust than parents who did not indicate discomfort (p=0.01). CONCLUSIONS: The CMI is feasible to administer in a clinic setting and demonstrates good internal consistency. It can be a useful tool to assess the effect of cultural mistrust on the healthcare decisions African-American parents make for their children. However, when measuring cultural mistrust in a healthcare setting, respondents' comfort with the survey questions should be assessed.