16
BLOOM SYNDROME Presentation by: Grace O’Toole aka: Bloom– Torre– Machacek syndrome

O'Toole Grace 11100387 Bloom Syndrome

Embed Size (px)

Citation preview

Page 1: O'Toole Grace 11100387 Bloom Syndrome

BLOOM SYNDROME

Presentation by:Grace O’Toole aka:

Bloom–Torre–

Machacek syndrome

Page 2: O'Toole Grace 11100387 Bloom Syndrome

History of Bloom

•1st identified by NY dermatologist Dr. David Bloom

•1st identified in 1954

Page 3: O'Toole Grace 11100387 Bloom Syndrome

Cause of Bloom• Autosomal recessive gene

characterized by high levels of sister chromatids

• Syndrome problem on chromosome 15

• Cells have genomic instability with excessive homologous recombination

• Increase in chromosome breakage/rearrangement

Page 4: O'Toole Grace 11100387 Bloom Syndrome

Cause: BLM gene•Gene encoding protein

RecQL3 helicase

•Mutation of BLM gene inactivate BLM protein’s DNA helicase activity or nullify protein expression

•Lack of BLM leads to increase mutations

Page 5: O'Toole Grace 11100387 Bloom Syndrome

Symptoms“Clinical Features”• Short stature

• Rash developing from sun exposure

• High pitched voice

• Facial features: long/narrow face, micrognathism (undersized jaw), prominent nose/ears

• Skin pigmentation change: hypo/hyper-pigment & cafe-au-lait spots (pigmented birthmarks)

• Telangiectasis (dilation of capillaries to appear red) in eyes

Page 6: O'Toole Grace 11100387 Bloom Syndrome
Page 7: O'Toole Grace 11100387 Bloom Syndrome

Con’t Skin Rash

•Erythematous (reddening), telangiectatic, infiltrated, & scaly

•Appears in butterfly-shaped patch of skin across nose/cheek & back of hands

Page 8: O'Toole Grace 11100387 Bloom Syndrome

Con’t Symptoms• Moderate immune deficiency {specifically

immunoglobulin classes} leads to recurrent pneumonia & ear infection

• Hypogonadism (failure to produce sperm) so infertile males

• Premature menopause for women

Complications-Chronic lung problems-Diabetes-Learning disabilities-Small # of mental retardation cases-Susceptibility to cancer

Page 9: O'Toole Grace 11100387 Bloom Syndrome

Bloom & Cancer•Elevated rate of mutation brings high risk of cancer

•Leukemia, lymphomas, & carcinomas

•Average age to develop cancer approximately 25 years old

Page 10: O'Toole Grace 11100387 Bloom Syndrome

Identification•Confirmed

through lab test: chromosome study

•PCR assay test for chromosome 15

Page 11: O'Toole Grace 11100387 Bloom Syndrome

Diagnosis Markers•Drastic

intrauterine growth deficiency with erythematous skin

•Small individual developing cancer

Page 12: O'Toole Grace 11100387 Bloom Syndrome

Frequency•Found in larger

quantity in Ashkenazic Jews (carriers 1/100)

•1/50,000 people affected of Central and Easter European Jewish background

Page 13: O'Toole Grace 11100387 Bloom Syndrome

Treatment for Identification

•Possible carriers: genetic counseling & genetic testing

•Known carriers: prenatal testing using cytogenetic or molecular methods

Page 14: O'Toole Grace 11100387 Bloom Syndrome

Treatment for Cases•No treatment

•Preventative Measures: surveillance for cancer & decreased exposure to sunlight/X-rays

•Possibility: bone marrow transplant

Page 15: O'Toole Grace 11100387 Bloom Syndrome

Bioethical Consequences

•Ethical problems to consider:

•Gene testing to be carriers calls into question for risk of child to be affected

•Sibling contempt with smaller sized Bloom Syndrome child compared to child not afflicted

Page 16: O'Toole Grace 11100387 Bloom Syndrome

Bibliography•Baxter, Sarah. "BLM Gene

Encodes a RecQ Helicase." Davidson.edu. Davidson College Molecular Biology, n.d. Web. 25 Feb. 2013. <http://www.google.com/imgres?imgurl=http://www.bio.davidson.edu/Courses/Molbio/MolStudents/spring2003/Baxter/BLM.gif>.

•O'Neil, Marla J. "Bloom Syndrome; BLM." Omim. Omim, Oct.-Nov. 2009. Web. 25 Feb. 2013. <http://omim.org/entry/210900>.