Lissencephaly with der(17)t(17;20)(p13.3;p12.2)mat.
The isolated lissencephaly sequence may be caused by point mutations of the LIS1 gene or by FISH-detectable microdeletions of the 17p13.3 region, which carries the LIS1 gene. These have various patterns of phenotypic presentations, including the Miller-Dieker syndrome (MDS). Approximately 20% of these deletions are associated with a derivative chromosome 17 inherited from a parent who has a balanced reciprocal translocation involving chromosome 17 and another chromosome. We report a case of lissencephaly associated with a maternally inherited unbalanced translocation involving chromosome arms 17p and 20p. This results in partial monosomy of 17p13.3-->pter and partial trisomy of 20p12.2-->pter. To our knowledge, this is the first report of a reciprocal translocation between 17p and 20p. Our patient has a combination of findings of the MDS and trisomy 20p, along with several unique anomalies not described in either of those two conditions. This report may contribute to the delineation of a phenotype resulting from partial monosomy 17p and partial trisomy of 20p.
Thomas
Mary Ann
MA
F. Clarke Fraser Clinical Genetics Unit, Division of Medical Genetics, Department of Pediatrics, Montreal Children's Hospital, Montreal, Quebec, Canada.
Duncan
Alessandra M V
AM
Bardin
Claudette
C
Kaloustian
Vazken M Der
VM
D000015:Abnormalities, Multiple / Q000235:genetics* / Q000473:pathology; D002871:Chromosome Banding; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics*; D002890:Chromosomes, Human, Pair 20 / Q000235:genetics*; D005192:Family Health; D006801:Humans; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000473:pathology*; D007621:Karyotyping; D008297:Male; D012640:Seizures / Q000473:pathology*; D013577:Syndrome; D014178:Translocation, Genetic