Omar S. Alfi

Partial Trisomy of the Long Arm of Chromosome No. 7

A case report on an infant with trisomy of the distal third of the long arm of chromosome No. 7 is presented.

HPLC analysis of uridine diphosphate sugars: decreased concentrations of uridine diphosphate galactose in erythrocytes and cultured skin fibroblasts from classical galactosemia patients

Abstract A high performance liquid chromatography (HPLC) method has been developed for the measurement of uridine diphosphate galactose (UDPGal) and uridine diphosphate glucose (UDPGlc) in erythrocytes and cultured skin fibroblasts of normal controls and galactosemia patients. The method incorporates an internal standard, UDPxylose, and alkaline phosphatase for the removal of nucleoside phosphates in the regions of UDPGal and UDPGlc in the chromatographic system. UDPGal and UDPGlc were separated on dual Dionex Carbo Pac PA-1 anion exchange columns. Samples derived from galactosemia patients without any detectable erythrocyte galactose-l-phosphate uridyl transferase (GALT) activity (GG), had in comparison to the controls significantly lower levels of UDPGal in both erythrocytes and cultured skin fibroblasts (P = 0.0001), while galactosemia patients with detectable GALT activity (GV) had normal levels of UDPGal. GG patients on oral uridine therapy had normal levels of UDPGal. These findings are consistent with our previous reports using an enzymatic method. In terms of absolute values, the values for both UDPGal and UDPGlc in erythrocytes by HPLC analysis were lower than those reported with the enzymatic method; however, in cultured skin fibroblasts, the values were similar with the two methods.

Double Autosomal Trisomy and Mosaicism for Chromosomes No. 8 and No. 21

This patient was found to have a previously unreported double trisomy for chromosomes No. 8 and No. 21. She was recognized to have Downs syndrome at birth, and her subsequent development was consistent with that diagnosis. Her general health was good and there were no features suggesting an additional chromosomal abnormality. At this time there is no clearly recognized phenotype associated with trisomy 8. Two non-disjunctional events, occurring in meiosis and/or post-zygotic mitosis, are possible explanations of the chromosomal abnormalities found in this patient.

Fucosidosis: Clinical, Pathologic, and Biochemical Studies of Five Patients

Fucosidosis is an inherited metabolic disorder in which deficiency of a-1-fucosidase activity results in accumulation of fucosyl compounds in lysosomes (6, 7, 24). Clinical manifestations reported include progressive motor and mental deterioration, coarseness of facial features, cardiomegaly, hepatomegaly, skeletal abnormalities and short stature (1,5,6,8,13). Initially many of the patients exhibit hypotonia, but progressive spasticity develops with time.

Regional mapping of the gene for human UDPGal 4-epimerase on chromosome 1 in mouse-human hybrids

Somatic cell hybrids between mouse and human cells containing two different reciprocal translocations involving human chromosome 1, 46,X,t(1;X)(q12;q26) and 47,XX,+21,t(1;17)(p32;p13), were studied for the expression of human uridine diphosphate galactose 4-epimerase (UDPGal 4-epimerase, E.C. 5.1.3.2) by starch-gel electrophoresis. Analysis of the hybrid clones for the expression of the enzyme and the presence of the translocation chromosome 1 has permitted the assignment of the gene for human UDPGal 4-epimerase to the pter yields p32 region of chromosome 1.

Two Children with a Partial Trisomy of Chromosome 15 (47,XX,+15): There Appears to Be No Constellation of Physical Findings That Are Characteristic of This Abnormality

From the Divisions of Child Development and Medical Genetics of the Childrens Hospital of Los Angeles, 4650 Sunset Boulevard, Los Angeles, California 90027: and the Department of Pediatrics of the University of Southern California School of Medicine and the Department of Anthropology, University of Toronto. Supported by grants from the Children’s Bureau of the Department of Health, Education and Welfare, Washington, D.C. Project #422, Mental Retardation Division (NR 93989-05-69), Social Rehabilitation Services, Department of Health, Education and Welfare and the Department of Public Health, State of California. ! OR ell NIC I ANS who serve the population of children with developmental anomalies, asking for a chromosome analysis has now become a routine procedure in practice. Recent advances in staining techniques have vastly increased the information that may be gained from SLICII StLI(lieS.’-5 This report con-

Genetic Disorders in Adolescents and Young Adults

While the nature of the environmental changes which trigger the expression of certain genetic disorders in adolescence is not completely understood, the metabolic and hormonal changes associated with sexual maturation probably have an important role. Examples of chromosomal abnormalities which may become evident in adolescence include Klinefelters syndrome and Turners syndrome. Two groups of gene abnormalities are given special emphasis: gene mutations expressed as abnormalities in sexual development, and those expressed as neurologic disorders.