Birth
of a healthy female after preimplantation genetic diagnosis
for Charcot-Marie-Tooth type X.
Iacobelli
M, Greco E, Rienzi L, Ubaldi F, Podini D, Nuccitelli A,
Tesarik J, Baldi M, Fiorentino F.
Reprod Biomed Online. 2003 Nov;7(5):558-62. |
The X-linked dominant form of Charcot-Marie-Tooth syndrome (CMTX)
is a clinically and genetically heterogeneous hereditary disorder
of the peripheral nerves caused by mutations in the GJB1 gene that
encodes a gap junction protein named connexin 32 (Cx32). Clinically,
CMTX is characterized by peripheral motor and sensory deficit with
muscle atrophy. A couple with a previous history of pregnancy termination
after being diagnosed positive for CMTX by chorionic villus sampling,
was referred for preimplantation genetic diagnosis (PGD). The female
partner carried the causative H94Q, characterized by a C-->G substitution
in codon 94 of exon 2 of the GJB1 gene. Embryos obtained after intracytoplasmic
sperm injection (ICSI) were evaluated for the presence of the mother's
mutation using polymerase chain reaction (PCR), followed by mutation
analysis performed using the minisequencing method. Amelogenin sequences
on the X and Y chromosomes were also co-amplified to provide a correlation
between embryo gender and mutation presence. A single PGD cycle was
performed, involving nine fertilized oocytes, five of which developed
into good quality embryos useful for biopsy. Two unaffected embryos
were transferred, resulting in a singleton pregnancy followed by the
birth of a healthy female.
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