Related Experiment Videos
New chromosomal syndrome: Miller-Dieker syndrome and monosomy 17p13
Abstract:
The Miller-Dieker Syndrome (MDS) consists of lissencephaly, characteristic facies, pre- and postnatal growth retardation, plus various other birth defects. Autosomal recessive inheritance has been presumed based on four reported families with two or more affected siblings. We present substantial evidence that monosomy 17p13.3 causes the MDS phenotype. This includes two patients with ring chromosome 17, one patient with a de novo 17p13 deletion, and one patient with monosomy 17p due to an unbalanced 7p; 17p translocation. We report the first prenatal diagnosis of MDS in a 20-week fetus from this latter family. Additionally, we report a balanced translocation between chromosome 17 and different autosomes (8, 12, and 15) in three of the four familial cases of lissencephaly. The finding of a chromosomal basis for this presumed autosomal recessive disorder significantly alters genetic counseling and makes prenatal diagnosis possible in some families.
Insights
Miller-Dieker Syndrome (MDS) is caused by a deletion on chromosome 17p13.3, not autosomal recessive inheritance. This finding enables prenatal diagnosis for affected families.
Area of Science:
- Genetics
- Developmental Biology
- Clinical Medicine
Background:
- Miller-Dieker Syndrome (MDS) is a congenital disorder characterized by lissencephaly, distinctive facial features, and growth retardation.
- Previously, MDS was presumed to be inherited in an autosomal recessive pattern, based on limited familial studies.
Observation:
- This study presents evidence linking monosomy 17p13.3 to the MDS phenotype.
- Case studies include patients with ring chromosome 17, a de novo 17p13 deletion, and an unbalanced translocation resulting in monosomy 17p.
- The first prenatal diagnosis of MDS was achieved in a fetus with an unbalanced 7p;17p translocation.
Findings:
- Monosomy 17p13.3 is identified as the cause of Miller-Dieker Syndrome.
- Balanced translocations involving chromosome 17 were observed in familial cases previously thought to exhibit autosomal recessive inheritance.
- The genetic basis of MDS is redefined from presumed autosomal recessive to chromosomal abnormality.
Implications:
- The identification of a chromosomal cause for MDS significantly alters genetic counseling approaches.
- Prenatal diagnosis of Miller-Dieker Syndrome is now feasible for families with identified chromosomal rearrangements.
- This research reclassifies the genetic etiology of MDS, impacting diagnostic strategies and family planning.