ABSTRACT
Sarcosinemia has been detected by routine screening of urine for metabolic and transport disorders in Massachusetts. Three infants who had sarcosinemia were detected through the neonatal urine specimen, an observed incidence of 1:350,000. A fourth child had sarcosinemia detected through family screening after his brother was found to have Hartnup disease by neonatal urine screening. These four children with sarcosinemia have plasma sarcosine concentrations ranging from 80 to 603 mumol/L and urine sarcosine from 2.1 to 9.4 mumol/mg of creatinine, findings similar to those reported for persons with sarcosinemia. No treatment has been given. At 3.8 to 15 years of age, the children had normal findings on physical examination and had no specific illnesses. Their full-scale IQ scores ranged from 89 to 111. The oldest child had a learning and emotional disorder, and one other child was emotionally unstable. It was concluded that sarcosinemia as a specific disorder is probably benign and that the mental retardation and dysmorphic features described in some affected persons are likely coincidental with the biochemical defect. The emotional disturbances that were encountered in two children are also probably coincidental but need further attention in this disorder.
Subject(s)
Amino Acid Metabolism, Inborn Errors/diagnosis , Sarcosine/blood , Adolescent , Affective Symptoms/complications , Amino Acid Metabolism, Inborn Errors/complications , Amino Acid Metabolism, Inborn Errors/epidemiology , Child, Preschool , Female , Humans , Intelligence , Male , Mass Screening , Massachusetts , Sarcosine/cerebrospinal fluid , Sarcosine/urineABSTRACT
Methylmalonic aciduria and Hartnup disorder are two rare autosomal recessively inherited metabolic disorders. We have described the coexistence of these disorders within the same pedigree in two unrelated families. This association was not found in 57 other families surveyed because of a proband known to have either methylmalonic aciduria or Hartnup disorder.
Subject(s)
Amino Acid Metabolism, Inborn Errors/genetics , Hartnup Disease/genetics , Malonates/urine , Methylmalonic Acid/urine , Adult , Amino Acid Metabolism, Inborn Errors/urine , Amino Acids/urine , Female , Genes, Recessive , Genetic Linkage , Hartnup Disease/urine , Humans , Infant , Male , PedigreeABSTRACT
Newborn blood from three siblings with prolidase deficiency contained no detectable prolidase activity. Umbilical cord blood contained no prolidase activity in one sibling and only 6.8% of control activity in another sibling. In prolidase deficiency the enzyme defect is expressed at birth, well before the appearance of skin ulcers, and is demonstrable in filter paper specimens of blood obtained for routine screening.
Subject(s)
Dipeptidases/deficiency , Child, Preschool , Dipeptidases/blood , Dipeptidases/genetics , Female , Fetal Blood/enzymology , Humans , Infant , Infant, Newborn , MaleABSTRACT
We describe a prospective study of histidinaemia. Probands and siblings (n = 21) with typical histidinaemia in 16 families were ascertained by newborn screening; diagnosis was confirmed by appropriate investigations in each subject; none had been treated by low histidine diet. The median age of subjects with histidinaemia was 9.5 y (mean 10.0, SD 3.5, range 6-18). Age-matched sib-pairs and their mothers were studied. IQ scores (Full Scale, Verbal and Performance Scores), Visual-Motor Integration Performance (Bender Gestalt and Koppitz scores), Wide Range Achievement Test (Reading and Mathematics), school performance, and psychological history were evaluated, as well as the medical history (pregnancy, delivery, neonatal, post-natal development). Findings were correlated with biochemical phenotype. CNS development in histidinaemic subjects (mean and distribution of scores) was normal; outlier values did not correlate with degree of histidinaemia. We can conclude that histidinaemia detected by newborn screening is a non-disadaptive phenotype.
Subject(s)
Amino Acid Metabolism, Inborn Errors/physiopathology , Histidine/blood , Adolescent , Adult , Child , Developmental Disabilities/epidemiology , Female , Humans , Intelligence Tests , Male , Phenotype , Prospective StudiesABSTRACT
Screening neonates for methylmalonic aciduria is part of routine screening for metabolic disorders in Massachusetts. The process of urine collection by the parent and transmitted to the central screening laboratory was described in a previous publication (Pediatrics 49: 825, 1972). The primary objective of screening for methylmalonic aciduria is to detect methylmalonic acidemia, an inherited organic acid disorder. During the most recent 5 1/2-year period when the sensitive fast blue B stain was used in the analysis, four infants with methylmalonic acidemia were detected among 293,535 screened. Additional infants and children who came to attention because of clinical illness or family study also could be readily detected. Prior to this period, 325,634 neonates had been screened with the aniline-xylose method, which proved to be not sensitive enough for the identification of methylmalonic aciduria. Some affected infants have responded well to therapy and are clinically normal while two have shown poor biochemical response and are developmentally delayed. Four children in two families appear to have a benign variant of methylmalonic acidemia. Based on these studies the observed incidence of methylmalonic acidemia in Massachusetts is 1:48,000. Screening for methylmalonic aciduria may be an appropriate addition to newborn screening programs.
