1022-7954/05/4108- © 2005 Pleiades Publishing, Inc.
Russian Journal of Genetics, Vol. 41, No. 8, 2005, pp. 936–940. From Genetika, Vol. 41, No. 8, 2005, pp. 1142–1146.
Original English Text Copyright © 2005 by Cvjeticanin, Marinkovic.
Congenital hip dislocation (
) is a prenatal mal-
formation in development of hip joints and its accom-
panying structures. Unless treated timely, this prenatal
malformation (which appears on one or both hip joints)
may develop in different degrees acquiring a form of
hypoplasia, subluxation, or the extreme worst form of
the hip joint luxation.
Some scientists support the opinion that CDH has
autosomal dominant inheritance , while one recent
study indicate that this malformation is probably inher-
ited as autosomal recessive . On the other hand,
some researchers think that CDH is polygenically
determined because environmental factors may play an
important role in the expression of this illness [3–5].
Another misunderstanding is whether dysplasia or lax-
ation of ligaments is being inherited, but most research-
ers think that both of these phenomena should be
observed together [5, 6].
Establishing genetic homozygosity in humans is a
very delicate assignment, because we know only a
small number of loci with alleles that determine an
exact biochemical process. Knowing the type of inher-
itance and variability, we can see that series of morpho-
physiological traits are under control of one or small
number of genes [7–9]. Using this information, several
authors of the Belgrade population-genetic school have
studied the distribution and frequency of a series of
extremely expressed recessive traits to estimate indi-
vidual and group differences (i.e., comparison between
ill and healthy individuals, pupils from special and reg-
ular schools, carriers of different blood types, members
of different ethnic groups) [10–17].
Assuming that CDH is genetically controlled dis-
ease, we made a hypothesis that a generally increased
homozygosity level, as well as changed variability in
the samples of such patients, could be a population-
genetic parameter for the prediction of this illness.
Numerous studies show that the percentage of ABO
and Rh blood types was found to be quite different in
different samples of patients [18–25]. According to
those ﬁndings, we assume that certain connection
between predisposition to CDH and frequencies of
ABO and Rh blood types exists.
MATERIALS AND METHODS
Taking into consideration the experience of numer-
ous scientists who studied the nature of the inheritance
of mono- and oligogenetically controlled qualitative
traits, we applied a methodology to estimate the pro-
portion of such homozygously recessive characters
(HRC-TEST of determination of homozygously reces-
sive characters in humans) in a sample of diseased and
healthy/control individuals (Table 1). In this study com-
Genetic Variability in the Group of Patients
with Congenital Hip Dislocation*
and D. Marinkovic
Institute of Human Genetics, Faculty of Medicine, University of Belgrade, Belgrade 11000;
Faculty of Biology, University of Belgrade
Received October 25, 2004
—Our study of genetic homozygosity degree includes an analysis of the presence, distribution, and
individual combination of 20 selected genetically controlled morphophysiological traits in the group of patients
= 93) with congenital hip dislocation (CDH) and in control sample consisting of schoolchildren from Bel-
= 200). Assuming that CDH is a genetically controlled disease, we made a hypothesis that an increased
homozygosity level, as well as the changed variability among the patients, could be a population-genetic param-
eter for the prediction of the illness. Taking into consideration our experience, as well as the experience of numer-
ous scientists who studied the nature of the inheritance of mono- and oligogenically controlled qualitative traits,
we applied a methodology to estimate the proportion of such homozygously recessive characters (HRC-TEST).
This population-genetic study did not only show statistically signiﬁcant difference of the middle values of
genetic homozygosity (CDH: 7.1
0.2; control: 5.2
0.1), but of the differences in the type of distribution too,
as well as the differences in the presence of certain individual combinations of such traits. The described meth-
odology can be used in further analyses, with hope that it can be applied as an early prognosis for decreased
resistance to different diseases.The frequencies of ABO blood types in the sample of CDH patients were similar
to the average value of the Serbian population, while the percentage of blood group A is slightly increased.
Comparing frequencies of Rh blood groups, there is no difference between tested samples.
* This text was submitted by the authors in English.