The Sage of Tea and the Inherited Metabolic Diseases

Background

Lu Yu (733-804 AD, Tang Dynasty) was an orphan raised and educated in a monastery. His profound knowledge of tea earned him the title "the Sage of Tea." This paper explores the possibility that Lu Yu may have been a patient of inherited metabolic diseases (IMDs), particularly phenylketonuria (PKU), considering historical records and unique aspects of his life.

Case Presentation

Examining Lu Yu's orphaned upbringing, clinical manifestations noted in his autobiography, dietary preferences, and the significance of his name, this study postulates that he may have had IMDs, notably PKU. His life choices, such as abstaining from meat and fish and favoring a low-protein diet during his time in a monastery, align with practices recommended for managing IMDs. The linguistic associations of his name further reinforce this hypothesis.

Conclusions

This investigation sheds light on the intriguing possibility that Lu Yu may have been affected by IMDs, notably PKU. By considering historical context, clinical correlations, dietary choices, and name symbolism, we offer a unique historical perspective on this celebrated figure's health. Further research could provide valuable insights into both his life and the broader medical practices of the Tang Dynasty.

Protein Substitutes in PKU; Their Historical Evolution

Protein substitutes developed for phenylketonuria (PKU) are a synthetic source of protein commonly based on L-amino acids. They are essential in the treatment of phenylketonuria (PKU) and other amino acid disorders, allowing the antagonistic amino acid to be removed but with the safe provision of all other amino acids necessary for maintaining normal physiological function. They were first formulated by a chemist and used experimentally on a 2-year-old girl with PKU and their nutritional formulations and design have improved over time. Since 2008, a bioactive macropeptide has been used as a base for protein substitutes in PKU, with potential benefits of improved bone and gut health, nitrogen retention, and blood phenylalanine control. In 2018, animal studies showed that physiomimic technology coating the amino acids with a polymer allows a slow release of amino acids with an improved physiological profile. History has shown that in PKU, the protein substitute's efficacy is determined by its nutritional profile, amino acid composition, dose, timing, distribution, and an adequate energy intake. Protein substitutes are often given little importance, yet their pharmacological actions and clinical benefit are pivotal when managing PKU.

Screening Out Controversy: Human Genetics, Emerging Techniques of Diagnosis, and the Origins of the Social Issues Committee of the American Society of Human Genetics, 1964-1973

In the years following World War II, and increasingly during the 1960s and 1970s, professional scientific societies developed internal sub-committees to address the social implications of their scientific expertise (Moore, Disrupting Science: Social Movements, American Scientists, and the Politics of the Military, 1945-1975. Princeton: Princeton University Press, 2008). This article explores the early years of one such committee, the American Society of Human Genetics' "Social Issues Committee," founded in 1967. Although the committee's name might suggest it was founded to increase the ASHG's public and policy engagement, exploration of the committee's early years reveals a more complicated reality. Affronted by legislators' recent unwillingness to seek the expert advice of human geneticists before adopting widespread neonatal screening programs for phenylketonuria (PKU), and feeling pressed to establish their relevance in an increasingly resource-scarce funding environment, committee members sought to increase the discipline's expert authority. Painfully aware of controversy over abortion rights and haunted by the taint of the discipline's eugenic past, however, the committee proceeded with great caution. Seeking to harness interest in and assert professional control over emerging techniques of genetic diagnosis, the committee strove to protect the society's image by relegating ethical and policy questions about their use to the individual consciences of member scientists. It was not until 1973, after the committee's modest success in organizing support for a retrospective public health study of PKU screening and following the legalization of abortion on demand, that the committee decided to take a more publicly engaged stance.

Genetics of Phenylketonuria: Then and Now

More than 950 phenylalanine hydroxylase (PAH) gene variants have been identified in people with phenylketonuria (PKU). These vary in their consequences for the residual level of PAH activity, from having little or no effect to abolishing PAH activity completely. Advances in genotyping technology and the availability of locus-specific and genotype databases have greatly expanded our understanding of the correlations between individual gene variant, residual PAH activity, tetrahydrobiopterin (BH4 ) responsiveness, and the clinical PKU phenotype. Most patients (∼76%) have compound heterozygous PAH gene variants and one mutated allele may markedly influence the activity of the second mutated allele, which in turn may influence either positively or negatively the activity of the biologically active heterotetrameric form of the PAH. While it is possible to predict the level of BH4 responsiveness (∼71%) and PKU severity (∼78%) from the nature of the underlying gene variants, these relationships remain complex and incompletely understood. A greater understanding of these relationships may increase the potential for individualized management of PKU in future. Inherited deficiencies in BH4 metabolism account for about 1%-2% of all hyperphenylalaninemias and are clinically more severe than PKU. Almost 90% of all patients are deficient in 6-pyruvoyl-tetrahydropterin synthase and dihydropteridine reductase.

Fifty years of phenylketonuria newborn screening - A great success for many, but what about the rest?

Guthrie's landmark discovery and the subsequent implementation of the first newborn screening programs for phenylketonuria (PKU) and other inherited errors of metabolism (IEM) could be - in a 50 year retrospective - easily considered among the greatest advances in medicine. They have not just improved the quality of hundreds of thousands of lives, but also transformed our understanding and approach to PKU and IEM in general. However, according to the available albeit very scarce data, many countries and regions seem not to share the benefits of the last 50 years of development. Many of them have not yet introduced the newborn screening for PKU or face significant problems in its implementation. In addition, the issue seems to be underrated by the relevant professional forums. Action to improve the current situation should urgently be taken.

Mandatory versus voluntary consent for newborn screening?

Virtually every infant in the United States undergoes a heel stick within the first week of life to test for a variety of metabolic, endocrine, and hematological conditions as part of state-run universal newborn screening (NBS) programs. The history of this mandatory public health program is examined, as well as whether the policy was morally justifiable. Three changes in NBS practice necessitate a re-evaluation of the mandatory nature of NBS. First is the adoption of NBS for hemoglobinopathies in the 1980s that led to the identification of many sickle cell carriers and carriers of other hemoglobin variants. In all other contexts, carrier testing requires consent, and there is no moral rationale why NBS ought to be exceptional. Second is the application of tandem mass spectrometry (MS/MS) to NBS in the 1990s that led to the identification of many metabolic conditions and variants, some of which were not treatable and others of which had unknown clinical relevance. To the extent that the conditions do not need emergent diagnosis and treatment, there is less justification for mandatory screening. Third, there is great interest in using residual blood spots for research, and the cornerstone of research ethics is the voluntary consent of the participant (or his or her proxy). These three changes support revising mandatory NBS with a tiered consent process to best balance respect for parental autonomy and the promotion of children's health.

Newborn screening in Spain, with particular reference to Galicia: Echoes of Louis I. Woolf

After briefly recalling the main events leading to the establishment of newborn screening programmes, this paper details the early history of their introduction in Spain and sketches their expansion to cover the whole Spanish population. Spain is exceptional in that its screening methods have in general been based on planar chromatographic techniques developed or inspired by Louis I. Woolf, rather than on bacterial inhibition tests, as is illustrated by the practice of the newborn screening laboratory of Galicia (N.W. Spain).

Pearl S. Buck and phenylketonuria (PKU)

In 1921, Pearl S. Buck gave birth to a daughter, Carol, who became severely retarded and was eventually institutionalized at the Vineland Training School in New Jersey. To help pay for her daughter's care, Buck wrote The Good Earth in 1931, and then other novels and biographies about her life in China, for which she was awarded the Nobel and Pulitzer Prizes, and honored around the world. Years later, she published The Child Who Never Grew, a short piece about her daughter's retardation that also revealed her desperate search for answers and good clinical care. Asbjørn Følling distinguished phenylketonuria (PKU) from other forms of childhood retardation in the mid-1930s, and new assays and biochemical findings eventually led to ways to circumvent the devastating effects of PKU. But for Carol Buck, these advances came too late. It was not until the 1960s that physicians confirmed that her severe retardation was caused by PKU.

The National Institute of Child Health and Human Development and phenylketonuria

The National Institute of Child Health and Human Development (NICHD) was established shortly after the Guthrie test for screening newborn infants for phenylketonuria (PKU) was introduced. The NICHD supported the study demonstrating the long-term efficacy of screening and a low-phenylalanine diet in preventing mental retardation. With the identification of the adverse impact on fetal development of high intrauterine phenylalanine exposure from a mother with PKU, the NICHD organized and supported the study reported here, demonstrating the protective effect of phenylalanine restriction of the mother's diet during pregnancy. The study provides clear guidance for the management of pregnancy in women with PKU.

Research design, organization, and sample characteristics of the Maternal PKU Collaborative Study

OBJECTIVE

The Maternal PKU Collaborative Study (MPKUCS) was initiated in 1984 by the National Institute of Child Health and Human Development (NICHD). The purpose was to assess the efficacy of dietary restriction of phenylalanine in reducing morbidity in offspring of women with hyperphenylalaninemia (HPA). A contract was awarded to Childrens Hospital Los Angeles as the Coordinating Center to provide implementation of the research protocol, data collection, and analysis.

METHODS

The Study included four regional contributing centers: Childrens Hospital Los Angeles (Western Region), Boston Children's Hospital (Northeast Region), University of Illinois (Midwest Region), and University of Texas Medical Branch, Galveston (Southeast Region). Within each region, many participating clinics were responsible for obstetric care, treatment, and monitoring protocols. In 1985, Canada joined the MPKUCS, and in 1992, Germany entered. They were selected because they provided dietary supplies and strong professional services. Acquisition began in 1984 and ended in October 1995. The study included 574 pregnancies in women with HPA and 100 control subjects matched on age, race, parity, and weeks of gestation. The sample included women with blood phenylalanine values >240 micromol/L, 66% of whom had classical PKU, 22% had atypical PKU, and 12% had mild HPA. Informed consents were obtained on all participants. The women ranged in age from 15 to 36 years of age, with a mean age at conception of 23 years. Teenage pregnancies accounted for 19%. Seventy-five percent graduated from high school. Offspring included 416 newborns, 317 of whom were evaluated at 4 years of age and 289 at 6 to 7 years. Follow-up involved medical, nutritional, psychosocial, and psychological assessments.

CONCLUSION

Women with PKU treated before conception and in control of their blood phenylalanine levels between 120 and 360 micromol/L (2-6 mg) exhibited normal pregnancies and neonatal outcome. Surprisingly, women who achieved control in the recommended range by 8 weeks of pregnancy also had a normal fetal outcome.

Asbjørn Følling and the discovery of phenylketonuria

In 1934, the Norwegian biochemist and physician Asbjørn Følling described an inherited metabolic disorder characterized by severe intellectual impairment, motor problems, and skin abnormalities. He found that affected individuals could be identified by the abnormal excretion of phenylpyruvic acid in their urine. The disorder, which Følling initially termed imbecillitas phenylpyrouvica, would later come to be known as phenylketonuria or PKU. The present paper focuses on the story of Følling's discovery and his subsequent contributions to the area of study. In the years that have followed, research on PKU has continued to play a major role in the neurosciences, shaping our understanding of genetic disorders, human metabolism, and brain development.

[Pearl S. Buck, Literature Nobel Price, and phenylketonuria: a moving relationship]

Art and Medicine, in some occasions have singular contact points. An example of this is the life of the North American writer Pearl S. Buck, a Litterature Nobel Prize winner in 1938, and her relation with phenylketonuria and mental retardation. The present paper is a biographical sketch of this brilliant writer, whose only daughter had phenylketonuria, an inborn error of metabolism of low frequency. If this disease is not treated, it may cause mental retardation. At the same time, we point out some of the highlights of the discovery of this disorder in Norway in 1934, and the description of its first treatment in 1953. At the present time, the mental retardation that this disease causes, can be prevented by means of the neonatal screening.

Henry Friesen Award Lecture. Work, the clinician-scientist and human biochemical genetics

The pursuit of human biochemical genetics has allowed us to understand better how the person with the (genetic) disease differs from the disease the person has and to develop the concept that genetics belongs in all aspects of health care. It is a perspective that comes quite readily to the clinician-scientist, and the restoration of that "species" in the era of functional genomics is strongly recommended. Garrod, the initial founder of human "biochemical genetics" belonged to the clinician-scientist community. Archibald Edward Garrod introduced a paradigm, new for its day, in medicine: biochemistry is dynamic and different from the static nature of organic chemistry. It led him to think about metabolic pathways and to recognize that variation in Mendelian heredity could explain an "inborn error of metabolism." At the time, Garrod had no idea about the nature of a gene. Genes are now well understood; genomes are being described for one organism after another (including Homo sapiens) and it is understood that genomes "speak biochemistry (not phenotype)." Accordingly, in the era of genomics, biochemistry and physiology become the bases of functional genomics, and it is possible to appreciate why "nothing in biology makes sense without evolution" (and nothing in medicine will make sense without biology). Mendelian, biochemical and molecular genetics together have revealed what lies behind the 4 canonical inborn errors described by Garrod (albinisn, alkaptonuria, cystinuria and pentosuria). Both older and newer ideas in genetics, new tools for applying them (and renewed respect for the clinician-scientist) will enhance our understanding of the human biological variation that accounts for variant states of health and overt disease. A so-called monogenic phenotype (phenylketonuria) is used to illustrate, in some detail, that all disease phenotypes are, in one way or another, likely to be complex in nature. What can be known and what ought to be done, with knowledge about human genetics, to benefit individuals, families and communities (society), is both opportunity and challenge.

Genetic disease since 1945

Although hereditary disease has been recognized for centuries, only recently has it become the prevailing explanation for numerous human pathologies. Before the 1970s, physicians saw genetic disease as rare and irrelevant to clinical care. But, by the 1990s, genes seemed to be critical factors in virtually all human disease. Here I explore some perspectives on how and why this happened, by looking at two genetic diseases--familial dysautonomia and phenylketonuria.

[Folling's disease]

Norway is a small country and we have few examples of medical scientists that has discovered and cultivated unknown territory. One very good example is the man who discovered the first link between metabolic disease and brain development. Asbjørn Følling was born in 1888 and discovered "his disease" (phenylketonuria = PKU) in 1934. This article gives a description of his life, discovery and work.

The discovery of phenylketonuria: the story of a young couple, two retarded children, and a scientist

In the 1920s, a little girl 3 years of age was brought from China to the United States by her American mother. Although the child was beautiful, her mind was not developing. The grief-stricken mother had consulted doctors in China, but they could neither diagnose the problem nor provide treatment. Morning and night the same questions occupied her mind: "What is the matter with my little girl? What is causing it? Is there any doctor, anywhere, who can cure her?" In the United States, she also went from doctors to psychologists to clinics looking for someone who could help. Finally, she went to the Mayo Clinic in Rochester, Minnesota. When she had answered all of the doctor's questions, and all the tests were finished, they still could not tell her what was wrong. There was nothing they could do. The disease from which the little girl suffered was unknown at that time. The mother was Pearl Buck. In her book, The Child Who Never Grew,(1) she described her first infant: "I remember when she was only 3 months old she lay in her basket on the sun deck of a ship. I had taken her there for the morning air. The people who promenaded on deck often stopped to look at her, and my pride grew as they spoke of her unusual beauty and of the intelligent look of her deep, blue eyes. I do not know at what moment the growth of her intelligence stopped, nor to this day why it did." This is a classical description of the disease, phenylketonuria (PKU). A perfect infant seems to develop normally for several months, then the development slows and at some point seems to stop. "Look at Mommy-look at Daddy!" the parents say as they try to coax the treasured smiles. Instead, the child drifts into a dream world and into irreversible mental retardation. All Pearl Buck's devotion and determination was of no avail in finding the cause of her child's retardation. It was to be another mother with the same commitment to her beautiful but retarded children, who approximately 10 years later followed the same path until she found a special doctor who unlocked the secret of the fate of these children. When 1 of the authors (W.R.C.) visited Miss Buck at her Pennsylvania home in 1960, she talked about how her daughter, Carol, then a grown person, had recently been diagnosed as having PKU, as a result of screening tests at the New Jersey Vineland Training School for the Mentally Retarded. During my visit and without disclosing the reason, Pearl Buck was invited to sniff a vial of phenylacetate crystals (the odor of stale urine samples from PKU patients). Immediately she recalled that Carol, as a child, had the same unusual odor. She was relieved that the prophesy of the last words in her book had come true: "What has been, need not forever continue to be so. It is too late for some of our children, but if their plight can make people realize how unnecessary much of the tragedy is, their lives, thwarted as they are, will not have been meaningless." These could be the words of Borgny Egeland, the mother of the children through whom the mystery of PKU was brought to light. Or they could express the conviction of the physician and biochemist, Asbjörn Fölling, who believed that "what was not known could be known." Through the discovery of PKU in these children, hope has been given to thousands of other children and to their grateful parents ().

Phenylketonuria and the peoples of Northern Ireland

The comparison of regional patterns of recessive disease mutations is a new source of information for studies of population genetics. The analysis of phenylketonuria (PKU) mutations in Northern Ireland shows that most major episodes of immigration have left a record in the modern genepool. The mutation 165T can be traced to the Palaeolithic people of western Europe who, in the Mesolithic period, first colonised Ireland. R408W (on haplotype 1) in contrast, the most common Irish PKU mutation, may have been prevalent in the Neolithic farmers who settled in Ireland after 4500 BC. No mutation was identified that could represent European Celtic populations, supporting the view that the adoption of Celtic culture and language in Ireland did not involve major migration from the continent. Several less common mutations can be traced to the Norwegian Atlantic coast and were probably introduced into Ireland by Vikings. This indicates that PKU has not been brought to Norway from the British Isles, as was previously argued. The rarity in Northern Ireland of IVS12nt1, the most common mutation in Denmark and England, indicates that the English colonialization of Ireland did not alter the local genepool in a direction that could be described as Anglo-Saxon. Our results show that the culture and language of a population can be independent of its genetic heritage, and give some insight into the history of the peoples of Northern Ireland.

Whatever happened to PKU?

The history of PKU is one of science in the discovery of an inborn error of metabolism and a chemical cause of mental retardation; and also one of technology with the development of methods to prevent disease. PKU is the classic example of success in the prevention of a genetic disease. Meanwhile, the science has continued to evolve over the 60 years since the discovery of PKU, generating new understanding of its clinical and metabolic phenotypes and about phenylalanine hydroxylation. At least five known genes are involved in hydroxylation of phenylalanine, synthesis of tetrahybrobiopterin and regeneration of this cofactor. The genes have been cloned and mutations characterized for several enzymes (GTPCH, 6-PTPS, PHS/DoCH, DHPR, PAH). A new animal model (the enu mouse) is contributing to knowledge about pathogenesis of brain disease and potential new treatments. The human phenylalanine hydroxylase gene (PAH) itself harbors 99% of the mutations causing hyperphenylalaninemia, over 170 different mutations have been identified at this locus. They cause loss of function; none affecting regulation has been identified. The aggregate PKU gene frequency at 1% is polymorphic in many human populations and mutations are highly stratified by region and population reflecting a variety of mechanisms (founder effect, genetic drift, hypermutability and, perhaps, selection) for their occurrence and distribution.

The discovery of phenylketonuria

In 1934, two severely mentally retarded children were examined by Dr Asbjørn Følling. He proved, by classical organic chemistry, that they excreted phenylpyruvic acid in their urine. The substance was also found in the urine of eight additional mentally retarded patients. Based on these observations, oligophrenia phenylpyrouvica (later termed phenylketonuria) was described as a new inborn error of metabolism. Følling later showed the pattern of an autosomal recessive genetic disease, probably caused by a block in phenylalanine metabolism, and that asymptomatic heterozygote carriers of the trait could be detected by phenylalanine loading. The stepwise elucidation and the line of reasoning are described. Phenylketonuria was the first inborn error of metabolism shown to affect the mind, and its importance as a model disease is emphasized. The article finally gives some insight into aspects of the personality of the discoverer.

Phenylketonuria revisited

This article describes the parts played by Bickel, Hickmans, Gerrard, and Woolf in the preparation of a formula low in phenylanine and in the treatment of the first child with phenylketonuria (PKU) with a low phenylalanine diet. As the child whom they were treating was 2 years old, and was already appreciably retarded mentally, the apparent improvement in her mental status was ascribed, by their medical colleagues, to the extra attention that the child was receiving and not to the biochemical changes noted in her blood.