<p><b>OBJECTIVE</b>To provide genetic
diagnosis and
counseling for a 2-year-old
girl with typical
Rett syndrome through analyzing the methyl-CpG
binding protein 2 (MECP2)
gene.</p><p><b>
METHODS</b>Potential
mutation of the MECP2
gene was screened by
DNA sequencing and
multiplex ligation-dependent probe amplification (MLPA)
analysis of members of the
family as well as normal controls.
Lymphocyte culture for
karyotype analysis was carried out for the
patient to exclude
chromosomal abnormalities.</p><p><b>RESULTS</b>The
karyotype of the
girl was normal. No variation of the MECP2
gene was detected in the
patient by direct sequencing. A heterozygosis variation, c.1072G>A in
exon 4 of the MECP2
gene was detected in a normal
female control, which was not found in other controls. The
son and
daughter of the
female control were respectively heterozygous and homozygous carriers of the same
mutation. By MLPA
analysis, a heterozygosis deletion of
exon 3 and part of
exon 4 was detected in the
patient.
cDNA amplification and sequencing confirmed the presence of a 1176 bp deletion (c.27-1202del1176). The same deletion was not detected in the
parents.</p><p><b>CONCLUSION</b>A large deletion in MECP2
gene was detected with MLPA in a
patient featuring typical
Rett syndrome. The same deletion was missed by sequencing
analysis. With
cDNA sequencing, the breakage point of the
mutation can be mapped precisely.</p>