1041 kindred include infantile metachromatic leucodystrophy and congenital nystagmus. At present it is not clear whether the occurrence of these conditions simply reflects the high degree of consanguinity in the population under study, or whether these genes are at high frequency in other Gypsy populations. We should welcome information on whether other workers have noted these or other inherited disorders in Gypsies from other parts of Britain and Europe.
SEX-CHROMOSOME LOSS IN HUMAN TUMOURS
-
p.
SIR--The letter by Dr Zankl and his colleagues (Jan. 25, 221) concludes that loss of sex chromosomes is a sign
of cell
high
and occurs more often in cells with a of division-e.g., cells from bone-marrow or
senescence
rate
tumours.
We have examined necropsy material from 150 untumours from men1 and found 32 tumours (21.4%) to be Y-negative. The mean age of the hosts of these Y-negative tumours was 63 years (range 37-85) and that of hosts of Y-positive tumours 62-7 years (range 24-89). More Y-negative tumours would be expected to develop in elderly males, if the proportion of cells having lost the Y chromosome increases with age as a general rule. However, the similarity of mean ages, in our series, of males with Y-negative and Y-positive tumours indicates that senescence plays an insignificant part in the formation of Y-negative tumours. Similarly, loss of the Y chromosome in already established malignant tumours seems to be uncommon. Among 84 cases of lung cancer in men there were 30 Y-negative tumours.2 All tumours were classified at the time of surgery in four clinical stages based on the TNM system. The Y-negative tumours comprised 28% of all cases in stage 11 of limited tumour growth, compared with 40% in stage iv. The difference is not significant
selected
Section of
Medical Genetics, Department of Medicine, Welsh National School of
HELP FOR THE DOCTORS
SIR Your leading article (April 12, p. 842) coincided appropriately with the publication of the Merrison report (April 19, p. 901; April 26, p. 969), with all its implications for the
a
are now
cell which haslost its Y chromosome
M. SELLYEI L. VASS.
GENETIC DISORDERS IN GYPSIES SIR Genetic differences between populations may be shown not only by the study of genetic markers such as blood-groups but also by differences in frequency of simply inherited diseases. Thus a high frequency of TaySachs disease is seen in Jews of East European origin, despite dispersal of the original population to many distant ,
countries. The Romany Gypsy population forms a comparable’ genetic isolate which has largely maintained its identity over the centuries since its original migration from India, as shown by linguistic and blood-group studies. In a genetic study of Welsh Gypsies we have found a high incidence of phenylketonuria (estimated prevalence 1/40; gene frequency 0-16). Other recessively inherited conditions in this’ ’
.
Vass, L., Sellyei, M. Lancet, 1973, i, 550. Sellyei, M., Ungár, I., Vass, L. Unpublished. Peterson, W. D., Jr., Simpson, W. F., Ecklund, P. S., Stulberg, new
Biol. 1973
, 242,
22.
to
describe rather different
care, then the distinction must be that the issues can be discussed constructively. Bicknell et al. make it clear that P.A.s are predominantly male and typically from a military background. Although there are more than 50 training programmes, the first was begun at Duke University as recently as 1966 by Estes,2 whose entrants now come from a wide variety of backgrounds and some come direct from high school. They may not have any previous experience in health care and only a few are qualified nurses. Owing to the requirements for state licensure of all P.A.s, their number throughout the U.S.A. is precisely known. It is crucial to their role that they are taught to perform tasks which have traditionally been exclusive to doctors and they are usually licensed to practise in relation to one specified physician. Nurse-practitioners, on the other hand, are usually female and have a nursing background1 and, presumably because they have become differentiated as a group from other nurses on an entrepreneurial basis and do not need additional licensure, their number in the U.S.A. is unknown. Bicknell suggests that in practice there is little difference in the tasks performed by well-trained nursepractitioners and by the P.A.s, but anecdote suggests otherwise, and in an area of rapid innovation in professional activities the boundaries between the two groups are bound to be blurred. In British hospitals, the P.A. perhaps has his counterpart in a composite of technical assistants from E.C.G. departIn the community it is ments to operating-theatres. exclusively the nurses who have been encouraged to extend traditional nursing to include activities, in the treatment room and the home, which probably resemble the combined functions of the P.A. and the nurse-practitioner in the U.S.A., though there is no comparative study of this aspect of medical’care. Presumably it is the spectre of the General Medical Council, as well as their own expectations of the nurse’s role, which have combined to persuade general practitioners that nurses are the only legitimate source of paramedical assistance. Nurses themselves have expressed misgivings3 about this assumption, and area nursing authorities may not be sympathetic either. To
made
Peterson et awl. observed a sharp fall in the number of cells with a Y chromosome after about 30 passages of finite cell-lines, derived from normal male skin, but the proportion of Y-positive and Y-negative cells has remained firmly constant in 20 passages of a permanent cell-line (MBA 9812) derived from a melanoma in a male. Therefore, we suggest that the unexpectedly high frequency of Y-negative tumours in men results mostly from chromosomal events during precancerous stages and that the contribution of cell ageing is less important.
C. S. Nature
used in the U.S.A.
hospital and in primary
gene loci.
1. 2. 3.
of medical manpower in the future.
people, and if, as seems likely, the same dualism is developing among paramedical assistants -in this country, both in
(possessing only a few active genes) would presumably be more likely to undergo successful neoplastic change than a cell which has lost another chromosome carrying important
Department of Pathology, Róbert Károly Hospital, H-1394 Budapest, XIII, Hungary.
use
Unhappily, you did not distinguish clearly the terms " physician’s assistant " (formerly " physician’s associate "), or " P.A.", and " nurse practitioner ", and the confusion became explicit in your last paragraph. The two terms
statistically. Consequently, loss of the Y chromosome occurs in the early phases of carcinogenesis, when the cells are already unstable but before malignant transformation is complete. At this stage
PETER S. HARPER E. MAIR WILLIAMS.
Medicine, Park, Cardiff.
Heath
1. 2. 3.
so
Bicknell, W. J., Walsh, D., Tanner, M. Lancet, 1974, ii, Estes, H. Update, 1974, 8, 829. Ferguson, M. Nursing Times, 1973, 69, p. 1410.
1241.
SEX-CHROMOSOME LOSS IN HUMAN TUMOURS
-
p.
SIR--The letter by Dr Zankl and his colleagues (Jan. 25, 221) concludes that loss of sex chromosomes is a sign
of cell
high
and occurs more often in cells with a of division-e.g., cells from bone-marrow or
senescence
rate
tumours.
We have examined necropsy material from 150 untumours from men1 and found 32 tumours (21.4%) to be Y-negative. The mean age of the hosts of these Y-negative tumours was 63 years (range 37-85) and that of hosts of Y-positive tumours 62-7 years (range 24-89). More Y-negative tumours would be expected to develop in elderly males, if the proportion of cells having lost the Y chromosome increases with age as a general rule. However, the similarity of mean ages, in our series, of males with Y-negative and Y-positive tumours indicates that senescence plays an insignificant part in the formation of Y-negative tumours. Similarly, loss of the Y chromosome in already established malignant tumours seems to be uncommon. Among 84 cases of lung cancer in men there were 30 Y-negative tumours.2 All tumours were classified at the time of surgery in four clinical stages based on the TNM system. The Y-negative tumours comprised 28% of all cases in stage 11 of limited tumour growth, compared with 40% in stage iv. The difference is not significant
selected
Section of
Medical Genetics, Department of Medicine, Welsh National School of
HELP FOR THE DOCTORS
SIR Your leading article (April 12, p. 842) coincided appropriately with the publication of the Merrison report (April 19, p. 901; April 26, p. 969), with all its implications for the
a
are now
cell which haslost its Y chromosome
M. SELLYEI L. VASS.
GENETIC DISORDERS IN GYPSIES SIR Genetic differences between populations may be shown not only by the study of genetic markers such as blood-groups but also by differences in frequency of simply inherited diseases. Thus a high frequency of TaySachs disease is seen in Jews of East European origin, despite dispersal of the original population to many distant ,
countries. The Romany Gypsy population forms a comparable’ genetic isolate which has largely maintained its identity over the centuries since its original migration from India, as shown by linguistic and blood-group studies. In a genetic study of Welsh Gypsies we have found a high incidence of phenylketonuria (estimated prevalence 1/40; gene frequency 0-16). Other recessively inherited conditions in this’ ’
.
Vass, L., Sellyei, M. Lancet, 1973, i, 550. Sellyei, M., Ungár, I., Vass, L. Unpublished. Peterson, W. D., Jr., Simpson, W. F., Ecklund, P. S., Stulberg, new
Biol. 1973
, 242,
22.
to
describe rather different
care, then the distinction must be that the issues can be discussed constructively. Bicknell et al. make it clear that P.A.s are predominantly male and typically from a military background. Although there are more than 50 training programmes, the first was begun at Duke University as recently as 1966 by Estes,2 whose entrants now come from a wide variety of backgrounds and some come direct from high school. They may not have any previous experience in health care and only a few are qualified nurses. Owing to the requirements for state licensure of all P.A.s, their number throughout the U.S.A. is precisely known. It is crucial to their role that they are taught to perform tasks which have traditionally been exclusive to doctors and they are usually licensed to practise in relation to one specified physician. Nurse-practitioners, on the other hand, are usually female and have a nursing background1 and, presumably because they have become differentiated as a group from other nurses on an entrepreneurial basis and do not need additional licensure, their number in the U.S.A. is unknown. Bicknell suggests that in practice there is little difference in the tasks performed by well-trained nursepractitioners and by the P.A.s, but anecdote suggests otherwise, and in an area of rapid innovation in professional activities the boundaries between the two groups are bound to be blurred. In British hospitals, the P.A. perhaps has his counterpart in a composite of technical assistants from E.C.G. departIn the community it is ments to operating-theatres. exclusively the nurses who have been encouraged to extend traditional nursing to include activities, in the treatment room and the home, which probably resemble the combined functions of the P.A. and the nurse-practitioner in the U.S.A., though there is no comparative study of this aspect of medical’care. Presumably it is the spectre of the General Medical Council, as well as their own expectations of the nurse’s role, which have combined to persuade general practitioners that nurses are the only legitimate source of paramedical assistance. Nurses themselves have expressed misgivings3 about this assumption, and area nursing authorities may not be sympathetic either. To
made
Peterson et awl. observed a sharp fall in the number of cells with a Y chromosome after about 30 passages of finite cell-lines, derived from normal male skin, but the proportion of Y-positive and Y-negative cells has remained firmly constant in 20 passages of a permanent cell-line (MBA 9812) derived from a melanoma in a male. Therefore, we suggest that the unexpectedly high frequency of Y-negative tumours in men results mostly from chromosomal events during precancerous stages and that the contribution of cell ageing is less important.
C. S. Nature
used in the U.S.A.
hospital and in primary
gene loci.
1. 2. 3.
of medical manpower in the future.
people, and if, as seems likely, the same dualism is developing among paramedical assistants -in this country, both in
(possessing only a few active genes) would presumably be more likely to undergo successful neoplastic change than a cell which has lost another chromosome carrying important
Department of Pathology, Róbert Károly Hospital, H-1394 Budapest, XIII, Hungary.
use
Unhappily, you did not distinguish clearly the terms " physician’s assistant " (formerly " physician’s associate "), or " P.A.", and " nurse practitioner ", and the confusion became explicit in your last paragraph. The two terms
statistically. Consequently, loss of the Y chromosome occurs in the early phases of carcinogenesis, when the cells are already unstable but before malignant transformation is complete. At this stage
PETER S. HARPER E. MAIR WILLIAMS.
Medicine, Park, Cardiff.
Heath
1. 2. 3.
so
Bicknell, W. J., Walsh, D., Tanner, M. Lancet, 1974, ii, Estes, H. Update, 1974, 8, 829. Ferguson, M. Nursing Times, 1973, 69, p. 1410.
1241.
