  We consider matrix orthogonal polynomials related to Jacobi type matrices of
weights that can be defined in terms of a given matrix Pearson equation.
Stating a Riemann-Hilbert problem we can derive first and second order
differential relations that these matrix orthogonal polynomials and the second
kind functions associated to them verify. For the corresponding matrix
recurrence coefficients, non-Abelian extensions of a family of discrete
Painlev\'e d-PIV equations are obtained for the three term recurrence relation
coefficients.
