2011 Group Project 2

From Embryology
Note - This page is an undergraduate science embryology student group project 2011.
2011 Projects: Turner Syndrome | DiGeorge Syndrome | Klinefelter's Syndrome | Huntington's Disease | Fragile X Syndrome | Tetralogy of Fallot | Angelman Syndrome | Friedreich's Ataxia | Williams-Beuren Syndrome | Duchenne Muscular Dystrolphy | Cleft Palate and Lip


Introduction

A congenital disorder is one which is present at birth. They are often abnormalities that arise from errors that occur during development of the fetus. Some congenital abnormalities are genetic, and often run in families while others are spontaneous and have no genetic linkages. DiGeorge syndrome is a congenital abnormality that is caused by the deletion of a part of chromosome 22. The symptoms and severity of the condition is thought to be dependent upon what part of and how much of the chromosome is absent. [1].

About 1/4000 children born are affected by DiGeorge syndrome, with 90% of these cases involving a deletion of a section of chromosome 22 [2]. DiGeorge is quite often a spontaneous mutation, but it may be passed on in an autosomal dominant fashion. Some families have many members affected.

DiGeorge is a complex syndrome and patient cases vary greatly. The common symptoms present across numerous patients include

  • Abnormal faces
  • Congenital heart defects
  • Hypoparathyroidism with hypocalcemia
  • Cognitive, behavioral, and psychiatric problems
  • Increased susceptibility to infections
  • Hypoplasia or absence of the thyroid and parathyroid glands [3]


DiGeorge is a serious syndrome affecting many of the body systems. The clinical manifestations of the chromosome 22 deletion are significant and can lead to poor quality and a shortened lifespan for the patient. As there is currently no treatment education is vital to the wellbeing of those affected, directly or indirectly by this condition. [4] Current and future research is aimed at how to prevent and treat the condition, there is still a long way to go but some progress is being made.

Historical Background

  • Angelo DiGeorge. In the mid 1960's, Angelo DiGeorge noticed a similar combination of clinical features in some children. He named the syndrom after himself. The symptoms that he recognised were hypoparathyroidism, underdeveloped thymus, conotruncal heart defects and a cleft lip/palate. [5]
  • 'Robert Shprintzen described patients with similar symptoms (cleft lip, heart defects, absent or underdeveloped thymus, hypocalcemia) and named the group of symptoms as velo-cardio-facial syndrome. [6]
  • 1980s technology develops to identify that these patients have part of a chromosome missing. [7]

Epidemiology

Etiology

Pathogenesis

Dianostic Tests

Diagnostic Test How it works Relevance to DiGeorge
Fluorescence in situ hybridisation [8] FISH FISH
Based on symptoms facial features hypercalcaemia
Ultrasound prenatal testing
Amniocentesis amniotic fluid prenatal
BACS- on beads technology test test


Fluorescent in situ hybridisation Based on a combination of symptoms

Ultrasound

Amniocentesis

BACS-on-beads technology

Clinical Manifestations

Treatment

Further research possibilities

Glossary

References


2011 Projects: Turner Syndrome | DiGeorge Syndrome | Klinefelter's Syndrome | Huntington's Disease | Fragile X Syndrome | Tetralogy of Fallot | Angelman Syndrome | Friedreich's Ataxia | Williams-Beuren Syndrome | Duchenne Muscular Dystrolphy | Cleft Palate and Lip