Are ABL and MTP markers at chromosome 4Q28 of patients with abetalipoproteinemia really the same loci?
Background: á¢¥talipoproteinemia is an extremely rare genetic
disorder of lipoprotein metabolism, associated with
various biochemical abnormalities, combined with clinical
malabsorption. The cause of the disease is considered to be
mutations in the Microsomal Triglyceride Protein gene.
Purpose: The aim of this study was to see if the locus Microsomal
Triglyceride Protein and ABL are identical in
patients with á¢¥talipoproteinemia. Another aim was to
provide information concerning the patient's karyotype.
Subjects-Methods: The study included seven persons: 3 patients
(a girl and two boys aged 32, 30 and 22 years respectively)
and their 4 healthy, first-degree relatives (two parents,
a brother and a sister). Three chromosome markers
(fibrinogen alpha at 4 q 28 (FGA), Gc and MNSs blood
groups) were tested. Cytogenetic studies were performed
on PHA stimulated peripheral blood cell cultures. Results:
Fibrinogen-alpha chromosome marker at 4 q 28 showed
absolute correlation in all three patients by inheritance of
the same maternal and paternal FGA alleles, whereas the
healthy siblings had other allelic constellations. The Gc and
MNSs genes were not informative. The karyotype of patients
and healthy members of the family was normal. Conclusion:
It is concluded that ABL and MTP (at 4 q 22-24) are probably
identical loci and should eliminate further on one designation.
The karyotype of patients with abetalipoproteinemia
Key Words: MTP gene, ?etalipoproteinemia, Greece,
Mutations, Chromosomes, Microsomal Transfer Protein