Qbank-Develpmental Genetics

Develpmental Genetics

Pdf Summary

The document appears to be a series of developmental genetics questions authored by Claudia Barnett, covering several genetic disorders and concepts. Each section presents a question or scenario regarding specific genetic conditions and requires matching with the correct answer from a given list. Key topics include transcription factor mutations, genetic syndromes, genetic pathways, cellular mechanisms, and limb anomalies associated with various syndromes.<br /><br />Some highlighted disorders and their associated genetic features include:<br />- **Saathre-Chotzen syndrome** linked to the TWIST transcription factor.<br />- **Joubert syndrome**, characterized by the "molar tooth sign" on MRI and associated with retinal dystrophy and ciliopathy.<br />- **Apert syndrome**, illustrating locus heterogeneity with mutations in FGFR2 and FGFR3.<br />- **Cornelia de Lange syndrome**, connected with NIPBL.<br />- **Langer-Giedion syndrome**, resulting from a microdeletion on chromosome 8q24.<br />- **Meckel syndrome**, evident by features like microcephaly, renal cysts, and polydactyly.<br />- **CHARGE syndrome**, often linked to mutations in the CHD7 gene.<br />- **Noonan syndrome**, which follows the RAS/MAPK pathway, indicated by signs like pulmonic stenosis, low-set ears, and short stature.<br />- **Smith-Lemli-Opitz syndrome**, pointing towards cholesterol metabolism pathway issues.<br /> <br />The document also describes genetic phenomena like:<br />- **Locus heterogeneity**, shown by different genetic loci leading to similar phenotypes, as in various syndromes.<br />- **Allelic heterogeneity**, indicating different alleles of a single gene causing different phenotypes.<br />- **Pleiotropy** and **expressivity**, reflecting a gene causing multiple or variable traits respectively.<br /><br />This comprehensive set of questions demonstrates how molecular genetics aids in diagnosing, understanding etiologies, and classifying developmental genetic disorders, focusing on the pathways and genetic mutations involved.

Keywords

developmental genetics

genetic disorders

transcription factor mutations

genetic syndromes

Saathre-Chotzen syndrome

Joubert syndrome

Apert syndrome

Cornelia de Lange syndrome

locus heterogeneity

pleiotropy