FALL 2012

Velocardiofacial syndrome, also known as DiGeorge syndrome, Sedlačlová syndrome, conotruncal anomalies face syndrome, Cayler syndrome, 22q11 deletion syndrome and CATCH 22 [7]. It is a genetic disorder affecting the pharyngeal and neurobehavioral development of an individual, which may result to the following health issues:
Facial appearance of individuals with VCFS. Permit to post the photo was acquired from the BMC Medical Genetics . Fernández et al. BMC Medical Genetics 2009 10:48 doi:10.1186/1471-2350-10-48

  • conotruncal congenital heart defects (CHD)
  • velopharygeal insufficiency
  • hypoparathyroidism
  • thymic aplasia or hypoplasia
  • craniofacial dysmorphism
  • learning disabilities
  • psychiatric disorders [2].

In some cases, individuals may have more obvious physical and mental features such as the following defects:
  • microcephaly
  • mental retardation
  • short stature
  • slender hands and digits
  • minor auricular anomalies
  • inguinal hernia [5].

There are many variations of phenotypes to every individuals. Some individuals may have a severe symptoms and others may have a moderate to minor symptoms. The pictures show some of the clinical features of VCFS. The prevalence of the disease ranges from about 1 in every 2000 to 1 in every 7000 live births [7]. Since the syndrome covers a wide range of phenotypic features, clinicians use certain clinical features that are easy to distinguish such as congenital heart disease (which occurs in approximately 70% cases of VCFS), palatal anomalies, chest vessel and ocular anomalies, psychiatric disorders, and language and speech impairment [7].

In the 1980s, VCFS was confirmed to be inherited as an autosomal dominant gene [7]. The cause of the syndrome, which is a deletion in chromosome 22q11.2 was found in 1992. To understand the syndrome, a genetic analysis of affected individuals were conducted by researchers. Using mouse model, researchers identified Tbx1 as the gene affected by the deletion [4].

Research Question:1. What is the role of Tbx1?2. Where does the mutation occurs?3. What causes the mutation to occur?4. What other species that has similar TBX1 gene with human?

What is the Role of TBX1 >>>