Jacobsen Syndrome

Jacobsen Syndrome Ashley Osborne Quesha McClanahan Orchi Haghighi

is a rare congenital disorder resulting from deletion of a terminal region of chromosome 11 that includes band 11q24.1. • It can cause intellectual disabilities, a distinctive facial appearance, and a variety of physical problems including heart defects and a bleeding disorder.

Young girl with Jacobsen Syndrome from Clermont, Florida. • Other common medical complications include recurrent infections, decreased platelet count • The syndrome derives its name from a Danish physician, Dr. Petra Jacobsen, who first described an affected child in 1973. • One copy of chromosome 11 is missing so an affected person has one out of a possible two copies of the genes in that region. • It is the loss of these genes that leads to the multiple problems found in Jacobsen syndrome.

Symptoms Hypertelorism- upper left & Ptosis- upper right Epicathal Folds- bottom left & Micrognathia- bottom right • Individuals with Jacobsen syndrome have a distinctive physical appearance. The face is characterized by wide-spaced eyes (hypertelorism), droopy eyelids (ptosis), redundant skin covering the inner eye (epicanthal folds), a broad or flat nasal bridge, a short nose with upturned nostrils, a small chin (micrognathia), low-set ears, and a thin upper lip.

Children with Jacobsen syndrome usually have some degree of mental retardation, ranging from mild to severe. • Nearly all affected individuals also have decreased muscle tone (hypotonia) or increased muscle tone (hypertonia) as well as motor delays. Occasionally, brain abnormalities are present.

Multiple types of physical abnormalities are known to occur in individuals with Jacobsen syndrome. • Congenital heart disease is present in about half of affected children • Other common internal abnormalities include pyloric stenosis, undescended testes, inguinal hernia, kidney defects, urinary tract abnormalities, craniofacial abnormalities, and external ear anomalies are frequent. Craniofacial Abnormalities

There are a variety of other health problems found in individuals with Jacobsen syndrome. Illnesses including recurrent respiratory infections • Also gastrointestinal problems such as gastroesophageal reflux and chronic constipation may occur.

Causes • It is caused by the loss of a small portion of a chromosome at conception. • In Jacobsen syndrome a small piece of the 11th chromosome is missing (or deleted) and this causes a range of clinical features in individuals with this condition.

The features are related to the genes that are absent from the small piece of chromosome 11 that is missing. • The reason for the loss of the piece of chromosome is not fully understood. • Jacobsen syndrome occurs more frequently in females than males.

Diagnosis • Most individuals with Jacobsen syndrome are diagnosed after birth. The diagnosis is usually made through a blood test called chromosome analysis in an infant or child who has mental retardation and a typical facial appearance. • The karyotype will show a deletion or rearrangement of the longer segment, known as the q arm, of one copy of chromosome 11.

Jacobsen Syndrome can be diagnosed before birth. There have been reports of prenatal diagnosis through amniocentesis after an ultrasound demonstrated one or more fetal abnormalities. • Another technique, known as FISH (fluorescent in-situ hybridization), may be used to further define the chromosome 11q deletion breakpoints

Treatment • Varies depending on the severity that may develop • Services and Programs-Physical and Speech Therapy-Social, Vocational and Medical services-Educational Support • Surgery • Genetic counseling

Impact • Family is emotionally disturbed • Many join a support group • Impacts learning disabilities and your ability to take care of yourself • Mobility

Bibliography • http://www.healthline.com/galecontent/jacobsen-syndrome-1/2 • http://www.wrongdiagnosis.com/j/jacobsen_syndrome/intro.htm • http://www.cafamily.org.uk/medicalinformation/conditions/azlistings/j10_3.html • http://www.wikigenes.org/e/gene/e/3719.html

Jacobsen Syndrome