DiGeorge syndrome
Emil Sagberg, Barak Moskovitz & Omar Magdi


History
•Also known as:
•22q11.2 deletion syndrome
•Velocardiofacial syndrome
•
•First described in 1968 by Angelo DiGeorge.
•
•The underlying genetics were found in 1981.
•
> DiGeorge syndrome - Wikipedia

Epidemiology
•DiGeorge syndrome affects one in 2000-4000 live births.
•
•Probably underdiagnosed due to some individuals having very few and mild symptoms – and therefore
not diagnosed
•
•It is one of the most common causes of intellectual disability due to a genetic deletion syndrome.

Etiology
•Caused by the deletion of a small segment of chromosome 22
•Typically deletion of 30-50 genes
•22q11.2 (long arm of chromosome 22, region 1, band 1, sub-band 2)
•Very rarely due to deletions on short arm of chromosome 10
•Autosomal dominant
•90% due to new mutation
•10% inherited from parents
•=> hypoplasia of 2nd & 3rd pharyngeal pouch derivates
•
•Very wide register of symptoms – due to incomplete penetrance
•

Symptoms
•Birth defects
•Congenital heart disease (40%) w. cyanosis
•Cleft palate (due to neuromuscular problems) (50%)
•Thymic hypoplasia - recurrent infections & autoimmune disorders due to altered T-cell response
•Parathyroid gland dysfunction – low PTH & hypocalcemia
•Kidney- & GIT problems
•Hearing loss (both sensorineural & conductive)
•

Cognitive- & psychiatric impairments
•Usually below borderline normal IQ
•Learning difficulties in 90%
•Speech & language
•Hypernasality, articulation errors & delayed vocabulary aquisition
•Autism-like behavior (severe hypocalcemia in early childhood)
•ADHD
•Seizures
•High risk of schizophrenia (25%) & psychosis
•High risk of early onset Parkinson's Disease
•

Diagnosis
•Diagnosis can be difficult due to great variability of symptoms and phenotypes between
individuals.
•Fluorescence in situ hybridization (FISH) is able to detect microdeletions that standard
karyotyping miss.
•Newer methods of analysis which can detect atypical deletions (not detected by FISH):
•Multiplex ligation-dependent probe amplification assay (MLPA)
•Quantitative polymerase chain reaction (qPCR)

Treatment
•No cure is known for DiGeorge syndrome.
•Although there is no cure, treatment can improve symptoms. The key is to identify each of the
associated features and manage each using the best available treatments.
•E.g., cardiac surgery is often required for congenital heart abnormalities. Hypoparathyroidism
causing hypocalcemia often requires lifelong vitamin D and calcium supplements, etc..
•

Sources
•https://www.mayoclinic.org/-/media/kcms/gbs/patient-consumer/images/2013/08/26/10/45/ds00738_ds009
98_im02607_fl7_cleft_palatethu_jpg.png
•https://scontent-prg1-1.xx.fbcdn.net/v/t1.0-9/35993643_630093554033065_3043657204562395136_n.jpg?_
nc_cat=103&_nc_sid=9267fe&_nc_ohc=PfhlYAE1zkUAX_PEeKw&_nc_ht=scontent-prg1-1.xx&oh=f26a8809bc64da7e
99ae0d037237acd6&oe=5EF93F63
•https://upload.wikimedia.org/wikipedia/commons/thumb/c/cb/DiGeorge_syndrome1.jpg/300px-DiGeorge_sy
ndrome1.jpg
•https://en.wikipedia.org/wiki/DiGeorge_syndrome
•