635 LOCALISED CLUBBING
SiR,-Dr. Eisinger’s suggestion (Aug. 31,
unmasked the clubbing tendency associated with bronchiectasis is intriguing and novel. Thickening of the terminal phalanx after injury is a common everyday experience, and probably as much clinical significance as a scar on the skin after laceration. Inspection of the fingers of people engaged in, for example, the building trade will attest to its frequency. I myself have an index finger clubbed subsequent to a crushing injury in a door: I have a clear chest X-ray, and no other disease whatever. What is really more to the point is how often localised clubbing occurs as part of a disease.
FAMILIAL XY GONADAL DYSGENESIS SiR,ŅThe interesting report of Sternberg and Barclay1 prompts us to report that we have recently found 3 cases of " pure " gonadal dysgenesis for which deletion of the long X chromosome arm has been postulated instead of an XY constellation.2 As yet in only 1 case with similar clinical and cytogenetic findings has an X-chromosome deletion been supposed.3 Hitherto the certain distinction between a Y chromosome and total deletion of the long X chromosome arm has not been possible.2 Patients with partial deletion of the long X chromosome arm show great similarity in part of the clinical picture of XY gonadal dysgenesis.2 The fact that there are apparently homologous genes on the short X chromosome arm and the Y chromosome4 prompts the assumption that very similar clinical pictures are seen in patients with total or partial deletion of the long X chromosome arm, deletion of the Y chromosome, or Y chromosome without function of the male determining factors. In the cases with the anomaly occuring in several sibships of the same family, preference has to be given to the assumption of an XY constellation. It seems improbable that the same rare anomaly of a heterosomal deletion arises de novo in several members of a family. This criterion may be useful in finding further distinctions between XY-constellation and X-deletion gonadal dysgenesis, because XY constellation and X deletion cannot yet be distinguished cytologically with
certainty. This study was done for the Association of EURATOM and the Society of Radiation Research for Haematology (contract no. 031-64-1 BIAD).
Hæmatology Institute of the Society of Radiation Research in Association with EURATOM, 1 Medical Clinic, University of Munich, Munich, Germany.
clear association between several chromosome abnormalities and leukxmia reported 6 suggests a relation between the father’s abnormality and the daughter’s death from acute leukxmia. More observations will be needed before deciding whether this is merely a fortuitous association. A full report of this family will be published elsewhere. RUBÉN LISKER Department of Genetics, MARÍA TERESA ZENZES Instituto Nacional de la Nutrición, MARÍA TERESA PONESCA. Mexico 7, D.F., Mexico.
DEFICIENT ARGININOSUCCINASE ACTIVITY IN BRAIN IN ARGININOSUCCINICACIDURIA SiR,--The activity of the argininosuccinase enzyme (L-argininosuccinate arginine lyase EC 4-3-2-1) was assessed in the brain tissue of a child who died from argininosuccinicaciduria and in the brain of 5 control children. The patient, who died at the age of 6 days, had the " maligform of argininosuccinicaciduria with neonatal onset nant and rapidly fatal evolution.’ Prominent clinical findings were progressively increasing respiratory distress and apathy, generalised hypotonia, and myoclonic seizures. The serumlevel of argininosuccinic acid reached 16 mg. per 100 ml. on the 4th day of life. All 5 control children, varying in age from 1 day to 4 years, died from a non-metabolic disorder. Argininosuccinase activity was quantitatively assessed by the method of Ratner8 as modified by Tomlinson and Westall,9 but the incubation-time was extended to 6 hours. Storage periods of the control brains varied from 1 to 6 months, while the patient’s brain was stored for 15 months. Storage for months at -30°C apparently did not result in any gross loss of enzyme activity. Argininosuccinase activity in the brain grey matter in the 5 control subjects ranged from 10-5 to 24-5 nmoles of urea per mg. protein per hour, and that in the patient was less than 2-3% of the mean value in the controls, as follows: "
H. J. KARL I. MACIAS-ALVAREZ.
YY SYNDROME IN A MEXICAN SIR,-So far reports of the XYY syndrome have been limited to Caucasians, the only exception being an American Negro described by Telfer et awl. The lack of reports from other places could conceivably be attributed to racial differences, though lack of awareness may well be the explanation. We here describe the first case seen in Mexico, in an individual of mixed Caucasian and Indian ancestry. The patient was found during a family study of his 2 daughters who were unusually tall (1-83 m. and 1-87 m.). Both had moderate mental retardation, and the younger died from acute leukaemia at age 13. The father is 45 years old, and 1-95 m. in height, and his intellect seems normal. He completed secondary school and now works as a clerk in an insurance company. He 1. 2.
is said to be of an aggressive nature and often changes jobs; however, he has no criminal record, and during youth did not participate in contact sports. Karyotype analysis of peripheralblood leucocytes showed 47 chromosomes in sixty mitoses studied, with an extra Y chromosome in all. It is possible that the unusual height of his daughters may be related to the XYY syndrome, though no proof of this exists, and information in the published reports on this aspect is scanty. The surviving daughter has a normal female phenotype, and normal menses, and her peripheral-blood karyotype is normal except for a slight increase in near-tetraploid cells. The
Sternberg, W. H., Barclay, D. L. Lancet, 1967, ii, 946. Karl, H. J., Back, F., Macias-Alvarez, I., Raith, L. Klin. Wschr. 1967, 24, 1225. Neuhauser, G., Back F. Med. Klin. 1968, 63, 836. 3. Becker, K. L., Paris, Z., Lambert, A. Proc. Staff Meet. Mayo Clin. 1963, 38, 389. 4. Ferguson-Smith, M. A. J. med. Genet. 1965, 2, 142. 5. Telfer, M. A., Baker, D., Longtin, L. Lancet, 1968, i, 95.
Up to now, deficient argininosuccinase activity has been demonstrated only in blood-cells and liver tissue from patients with argininosuccinicaciduria. When the widespread distribution of the enzyme in animals is considered, 10-12 there is no doubt that, beside liver, brain, and blood-cells, other tissues will also be shown to have deficient argininosuccinase activity in patients with argininosuccinicaciduria. J. KINT Department of Pædiatrics, D. CARTON. University of Ghent, Belgium. 6. 7. 8.
9. 10. 11. 12.
Miller, R. New Engl. J. Med. 1966, 275, 87. Baumgartner, R., Scheidegger, S., Stalder, G., Hottinger, A. Helv. pœdiat. Acta, 1968, 23, 77. Ratner, S. in Methods in Enzymology (edited by S. P. Collowick and N. O. Kaplan); vol. II, p. 364. New York, 1955. Tomlinson, S., Westall, R. G. Nature, Lond. 1960, 188, 235. Ratner, S., Pappas, A. J. biol. Chem. 1949, 179, 1199. Ratner, S., Petrack, B. ibid. 1953, 200, 175. Walker, J. B. Proc. Soc. exp. Biol. Med. 1958, 98, 7.