Genetic analysis for carrier diagnosis in hemophilia A and B in the Mexican population: 25 years of experience.

Our 25 years of experience in carrier diagnosis of hemophilia A (HA) and B (HB) in Mexican population comprises linkage analysis of intragenic F8/F9 neutral variants along with, in severe HA (SHA), detection of F8 int22h and int1h inversions. In symptomatic carriers (SCs) we explored Lyonization to explain their symtomatology. From a DNA-Bank of 3,000 samples, intragenic restriction fragment length (RFLPs) and short tandem repeats (STRs) of F8/F9 genes were assessed by PCR-PAGE and GeneScan.

A teenager with a t(X;17)(q22;q25) and ovarian failure.

Background: The effects of a balanced X; Autosome translocation [t(X;A)] on the fertility of carrier females led to the definition of the Xq13-->q27 region as critical for ovarian function and reproductive lifespan. We describe here a teenager with ovarian failure likely due to a balanced t(X;17)(q22;q25).

Case: The 16 year-old patient presented with secondary amenorrhea.

[Assessing the inactivation pattern in chromosome X among symptomatic carriers and women with haemophilia].

X chromosome inactivation is a stochastic event that occurs early in female embryo development to achieve dosage compensation with males. Certain genetic mechanisms affect the normal process causing a skewed X inactivation pattern which has clinical relevance in female carriers of X-linked recessive disorders, like haemophilia. The most commonly used assay to evaluate the X inactivation pattern is the PCR amplification of the human androgen receptor gene (HUMARA).