Family study in familial hypercholesterolemia with a receptor-negative homozygous 9-year-old boy

A 2-year-old boy showed massive xanthomas, especially tendon xanthomas and cutaneous xanthomas on the knees. When presented to us at the age of 9 years, his total cholesterol was 700-1100 mg/dl, LDL-cholesterol 600-1000 mg/dl, and triglycerides were normal, which is the constellation of hyperlipoproteinemia type IIa. LDL receptor studies showed 3% of normal binding activity, which defines the receptor-negative form of homozygous familial hypercholesterolemia (FH). Remarkably there was no sign of coronary heart disease in angiography. Three great-grandparents and the paternal grandfather (at 44 years) died from cardiovascular disease. The maternal grandmother is heterozygote for FH as well as three siblings of the father. In all family members we determined apolipoprotein B, apo-E-phenotype and the lipoprotein fraction Lp (a). In this family there seems to be no genetic coupling between the LDL receptor gene and the gene for Lp (a).- Therapy of heterozygous FH should start as early as possible, before symptoms appear. Therefore pediatricians should be very critical about the cholesterol values of their little patients.

Metabolic conversion of L-[U-14C]phenylalanine to respiratory 14CO2 in healthy subjects, phenylketonuria heterozygotes and classic phenylketonurics

Ten healthy volunteers, 12 classic phenylketonuria (PKU) heterozygotes, and 5 classic phenylketonurics have been loaded orally with a mixture of 5 microCi of L-[U-14C]phenylalanine plus 25 mg/kg of L-[2H5]phenylalanine. For 3 h thereafter, carbon-14 activity in expired air and total carbon dioxide were measured continuously and the levels of L-phenylalanine and L-tyrosine in plasma were determined in six blood samples. After 3 h, 15.1 +/- 2.1% of the applied dose of radioactivity was recovered in the expired air of the healthy subjects, compared to 10.1 +/- 2.2% for PKU heterozygotes and 0.32 +/- 0.18% for classic phenylketonurics. The integrated activity expired provides a discrimination between normals and PKU heterozygotes with a classification error of about 13% compared to an error of about 9% based on the fasting L-phenylalanine over L-tyrosine ratio. A combination of these two parameters in a two-dimensional discriminatory analysis reduces the classification error to less than 1%. An intraindividual correlation between the absolute activity expired and the formation of L-[2H4]tyrosine formed is shown, confirming that ring hydroxylation of L-phenylalanine to L-tyrosine is mandatory in the catabolism of L-phenylalanine to carbon dioxide.

[Neonatal screening for mucoviscidosis using the BM-test-meconium]

In the Federal Republic of Germany screening for cystic fibrosis by the albumin content of meconium (BM-test) is performed on most newborns. In this paper arguments for and against this test are discussed. Arguments in favour of BM-test-screening are the possibility of early diagnosis, early treatment and genetic counseling. Drawbacks of the test are false positive and false negative results. The authors conclude that this screening test should not be performed.

Detection of heterozygous carriers for phenylketonuria by a L-[2H5]phenylalanine stable isotope loading test

Oral loading with 25 mg/kg of pentadeuterated L-phenylalanine has been used for the discrimination between normozygous subjects and carriers for phenylketonuria. The test provides five types of data derived from plasma Phe and Tyr concentrations on which the discrimination can be based: fasting phenylalanine/tyrosine ratios, total Phe levels, total Phe/total Tyr ratios, absolute L-[2H5]phenylalanine plasma levels, and L-[2H5]Phe/L-[2H4]Tyr ratios. Absolute L-[2H4]Tyr and total L-Tyr concentrations provide the poorest discrimination with statistical classification errors around 30%. The corresponding classification error of fasting Phe/fasting Tyr ratios was circa 13%, and both labelled Phe/labelled Tyr and total Phe/total Tyr concentration ratios gave minimal errors below 2%.

[Subacute citrullinemia--diagnosis and course up to 4th year of life]

The article reports on an infant which first in age of nine months and then again in age of 1.6 years had an episode of stupor. Laboratory investigation showed hyperammonemia and high values of transaminases. The differential diagnostic check up led to the diagnosis of citrullinemia in the age of 1.7 years by amino acid chromatography. The diagnosis could be confirmed by measuring enzyme activity in the liver. Therapy is protein-low feeding and supplementation of essential amino acids and arginine. A therapeutic trial with additional sodium benzoate did not show a positive effect. The patient made a significant step backwards in development during the second episode of stupor; however in the following months the retardation could be reduced markedly.

[Excretion of normal and modified RNA catabolites and creatinine in the urine as a function of nutrition in children]

The urinary excretion of 5 modified and 2 unmodified RNA catabolites and of creatinine has been investigated in two children aged 71/2 and 6 years under different isocaloric diets over 5 days each (phase I-III) and compared with the excretion values during a 12-day and libitum food intake (phase 0). On a diet (phase I) extremely rich in nucleic acids (meat) there is only a slight increase of the modified RNA catabolites and a pronounced increase of creatinine in urine. On a protein-rich diet free from nucleic acids (phase II) the urinary RNA catabolites largely parallel the values seen under ad libitum food intake. On a diet virtually free of nucleic acids and protein (phase III) there is a markedly decreased excretion of modified RNA catabolites. It is concluded that modified RNA catabolites in the urine are mainly of endogenous origin. These "one-way catabolites" permit an assessment of the RNA turnover. Thus, they can serve as a new sensitive biochemical criterion for anabolic and catabolic situations, respectively.

[Excretion of methylated nucleosides in the initial therapy phase in a case of anorexia nervosa]

The urinary excretion of six methylated ribonucleosides was measured in a case of anorexia nervosa during the first eight weeks of therapy. Four phases can be distinguished. Highly elevated values are found in a clearly catabolic situation. Immediately after onset of therapy when catabolism is stopped but nutrition still inadequate the excretion of RNA-catabolites is lowered markedly. As soon as normocaloric nutrition is reached after two weeks, a short but clearcut peak-excretion can be observed. Finally, the excretion of methylated RNA-catabolites is stabilized on an intermediate level after three to six weeks, when nutrition is constantly normocaloric and weight continues to increase linearly.

[Age dependency of normal and modified nucleobases in urine in correlation to growth velocity (author's transl)]

Up to now no age-correlated normal values of normal and modified nucleobases in urine have been published. In this paper such normal values are presented, obtained from 116 healthy subjects from 0 to 16 years by high performance liquid chromatography of creatinine-correlated single urine specimens. A narrow correlation between the excretion of nucleobases and growth velocity was found. A polynomial function including the puberal growth spurt could be fitted to the analytical data. It is felt that this method should be suitable to assess growth processes of different kinds, e.g. effects of nutrition or drugs and hormones on growth velocity, furthermore intrauterine and malignant growth.

[Twenty years of urology in a children's hospital (1954--1974). Together with an epicrisis of 101 children with bilateral anomalies of the urinary passages, operated on in the first year of life (author's transl)]

This work encompasses a 20-year period, during which a urologist spent an important part of his time in a children's hospital, because of his conviction that attemps at effective treatment of urinary passage anomalies in childhood have a chance only when treatment is begun as early as possible. A report is presented on 101 children with bilateral, severe urinary passage anomalies, who were operated on in the first year of life, with the goal of early, total correction. The following experiences are of general significance: 1. The earlier the symptoms -- in 90% of cases, pyuria -- the more severe are the findings. -- 2. Males are primarily affected, here at a ratio of 7:3. As a result, pyuria in infants must be explained urologically, particularly when it occurs in males. -- This report is a plea for early, total correction and against periodic urinary drainage. Results show a 50% decrease in infections, flow disturbances, and biochemical changes, as well as a postoperative burst of growth also in 50% of cases. Cinematographic examinations show normal peristalsis even after skeletization and drastic reduction of a megaureter. The mortality was 9%, in the first year of life, 6%. Surprisingly, the result was not influenced by the presence or absence of reflux, but rather by stigmas and inferior development. Reflux had probably already played its fateful part in this severe bilateral disease, so that antireflux plastic surgery loses its prophylactic value. Compared with reports of experiences with periodic urinary drainage, our aim is to disprove the argument that, in difficult cases, total correction is dangerous: on the contrary, our results are better and coincide with the experiences of Hendren. Although Bischoff did not live to see the results of this work, in retrospect, our results bear out his pioneering concepts and ideas.