Treatment of hyperargininaemia due to arginase deficiency with a chemically defined diet.

A brother and sister aged 11 and 17 years have been reported previously to have hyperargininaemia and arginase deficiency: they were treated with a semi-synthetic diet consisting of fat, carbohydrate, minerals, vitamins and essential amino acids in amounts equivalent to 0.55-0.65 g protein kg-1 day-1 for 2 years. Plasma arginine levels fell from 0.50-0.90 mumol/1 to 0.13-0.30 mumol/1 (normal range 0.02-0.15). Increased concentrations of arginine in the cerebrospinal fluid (CSF) fell from 0.069-0.098 mumol/l to 0.040-0.056 mumol/l (normal mean +/- SD = 0.020 +/- 0.006). Dibasic aminoaciduria returned to normal within 1 week. Substitution of the keto-acid analogues of five essential amino acids in the formula lowered arginine concentrations further, but proved to be unpalatable. Urinary concentrations of orotic acid, uridine and uracil fell toward normal but remained increased, even when the plasma ammonia concentration was measured as normal. Both patients showed a stable clinical improvement.

The campomelic syndrome in a singleton and monozygotic twins.

We describe here three patients with the campomelic syndrome, two of whom were identical twins. Both twins were phenotypically female but had an XY chromosome complement.

Long-limbed campomelic dwarfism. A radiologic and pathologic study.

Comparison of the roentgenographic and pathologic features of a case of classic, long-limbed campomelic dwarfism with those of previously reported cases leads to the conclusion that the bony abnormalities in this disorder are not due to an intrinsic abnormality of cartilage formation or of osteoblast or osteoclast function. Likewise, no defect in bone collagen, ground substance, or mineralization is evident. The bowing of the long bones may be the result of poorly understood muscular stresses operative in utero. Widespread defects in other organ systems are present, with considerable variation from patient to patient. Phenotypic females with disorder commonly suffer from gonadal dysgenesis. Autosomal recessive inheritance is suggested for a subgroup of these patients, but environmental factors may be causative in some instances.

Tetrasomy 9p: confirmation by enzyme analysis.

A 4-day-old Caucasian male presented with midline defects of the skull and face and extensive skeletal malformations. Chromosome analysis of peripheral blood lymphocytes showed tetrasomy 9p (47,XY, + i(9p) with no evidence of mosaicism. Confirmation of the cytogenetic interpretation was obtained from the assay of the enzyme galactose-1-P uridyl transferase, the locus for which is on 9p, which showed twice the normal activity.

Expression of GALT in 9p chromosome alterations: assignment of GALT locus to 9cen leads to 9p22.

Determination of activity and electrophoretic mobility of GALT in patients with various chromosome 9 deletions and duplications confirms the assignment of its locus to 9p and suggests its locus is in the segment 9cen leads to p22. Two inversions of 9qh (inv(9)(p11q12)) did not alter GALT expression.

Familial pericentric inversion of chromosome 8 : is breakpoint p22q23 important in the formation of unbalanced recombinants?

A female infant with multiple congenital anomalies was ascertained to have 46,XX,rec(18)dup q, inv(8)(p23q22) through a carrier father with pericentric inversion of chromosome 8 (46,XY,inv(8)(p23q22). Comparison of the clinical and cytogenetic findings are made with previously published similar cases.

Assignment of PGM3 to the long arm of human chromosome 6. Studies using Chinese hamster X human cell hybrids containing a human 6/15 translocation.

Hybrids derived from the fusion of thymidine kinase deficient Chinese hamster cells and human cells carrying a 6/15 translocation, 46,XX,t(6;15)(cen;p13), were analyzed for the expression of human PGM3, GLO and ME1. The results show that PGM3 and ME1 are on the long arm and GLO is on the short arm of human chromosomes 6.

18p--syndrome resulting from translocation (13a;18q) in a mildly affected adult male.

The patient was a 27-year-old male with short stature, borderline mental deficiency, strabismus, and a short fourth metacarpal. His karyotype showed deletion of the short arm of a chromosome 18 as the result of de novo fusion centric translocation between chromosomes 13 and 18 (45,XY, --13, --18, +t(13;18) (13qter yields cen yields 18qter).

Partial trisomy of 13(pter to q12) due to 47,XY, + der(13),t(13;22)(q12;q13)mat.

A 36-month-old boy presented with short stature, short neck, shield-shaped chest, and mental retardation. Chromosome analysis showed trisomy for the short arm and the proximal protion of the long arm of chromosome 13 [47,XY, + der(13),t(13;22)(q12;q13)mat]. The patient's mother has a balanced translocation between the long arms of chromosomes 13 and 22 [46,XX,t(13;22)(q12;q13)]. The patient's neutrophils showed an elevated number of nuclear projections and his fetal hemoglobin level was undetectable.

Chromosome 7 short-arm interstitial deletion (p14).

A 13-year-old girl presented with microcephaly, short and broad neck, low posterior hairline, congenital heart disease, limitation of joint movement, and mild mental retardation. Chromosomal analysis showed interstitial deletion of band p14 of the short arm of chromosome 7. The patient's physical and cytogenetic findings are compared with those of five other patients with 7p- deletions.