  In this paper we consider discrete-time dynamical systems generated by
gonosomal evolution operators of sex linked inheritance. Mainly we study
dynamical systems of a hemophilia, which biologically is a group of hereditary
genetic disorders that impair the body's ability to control blood clotting or
coagulation, which is used to stop bleeding when a blood vessel is broken. We
give an algebraic model of the biological system corresponding to the
hemophilia. The evolution of such system is studied by a nonlinear (quadratic)
gonosomal operator. In a general setting, this operator is considered as a
mapping from $\mathbb R^n$, $n\geq 2$ to itself. In particular, for a gonosomal
operator at $n=4$ we explicitly give all (two) fixed points. Then limit points
of the trajectories of the corresponding dynamical system are studied. Moreover
we consider a normalized version of the gonosomal operator. In the case $n=4$,
for the normalized gonosomal operator we show uniqueness of fixed point and
study limit points of the dynamical system.
