A neural crest deficit in Down syndrome mice is associated with deficient mitotic response to Sonic hedgehog.

Trisomy 21 results in phenotypes collectively referred to as Down syndrome (DS) including characteristic facial dysmorphology. Ts65Dn mice are trisomic for orthologs of about half of the genes found on human chromosome 21 and exhibit DS-like craniofacial abnormalities, including a small dysmorphic mandible. Quantitative analysis of neural crest (NC) progenitors of the mandible revealed a paucity of NC and a smaller first pharyngeal arch (PA1) in Ts65Dn as compared to euploid embryos.

Prenatal detection of a subtle unbalanced chromosome rearrangement by karyotyping, FISH and array comparative genomic hybridization.

Objectives: To explore the advantages and limitations of comparative genomic hybridization to BAC arrays (array CGH) for prenatal diagnosis of a fetus with anomalies and a chromosome abnormality.

Methods: We used karyotype analysis, FISH and array CGH to investigate an unbalanced chromosome rearrangement.

Results: We report a case of a fetus with ultrasound anomalies at 11 weeks' gestation and an unbalanced chromosome translocation [46,XX,der(13)t(2;13)(p25.

Microphthalmia with linear skin defects (MLS) syndrome evaluated by prenatal karyotyping, FISH and array comparative genomic hybridization.

Objective: To explore the utility of comparative genomic hybridization to BAC arrays (array CGH) for prenatal diagnosis of microphthalmia and linear skin defects syndrome.

Methods: We used karyotype analysis, FISH and array CGH to investigate an X;Y translocation. Replication studies were done on cultured amniocytes and lymphoblasts.