Causes of disorder
For the child to have xeroderma pigmentosum, the parents must be a ___ for the gene.
Carrier
About a quarter of patients experience this symptom:
Neurological/intellectual complications
True or false: A blood and urine test can indicate if someone has xeroderma pigmentosum.
False
Which types of sunscreens are used to manage the symptoms of this disorder?
Physical and chemical sunscreens
What is the nickname for people with xeroderma pigmentosum
Children of the night or moon children
Why are middle eastern people more likely to have xeroderma pigmentosum?
Cousin/consanguineous marriages
This appears on sun-exposed areas before age 2 and is characterized by small, flat, brown spots.
Freckles (or lentigines)
What is it called when doctors take a small sample of tissue (skin in this case) to diagnose skin cancer or related illnesses?
Biopsy (Specifically skin biopsy)
True or false: People with xeroderma pigmentosum wear protective clothing to avoid exposure to UV radiation.
True; certain clothing can be UV- protective.
What does derma in xeroderma pigmentosum mean?
Derma = Skin
Name 1 of the 8 genes that must be mutated to have this disorder.
• XPB gene, XPC gene, POLH gene, XPA gene, XPE gene, XPG gene, XPF gene, and XPD gene
True or false: People with Xeroderma Pigmentosum are 1,000,000% more susceptible to skin cancer
True, 10000x in percentage is 1,000,000%
What does gene sequencing do?
Pinpoints the exact mutated gene and its complementation group.
Why is there no cure for xeroderma pigmentosum?
Because it's a permanent, inherited genetic disorder, or because it's caused by mutations in at least eight different genes that alters DNA repair.
What is the median (average) age for developing skin cancer when you have xeroderma pigmentosum
9 years old
Nucleotide changes in specific genes can disable what mechanism in a xeroderma pigmentosum patient?
The Nucleotide Excision Repair System (NER)
Which 2 subtypes of xeroderma pigmentosum have the most severe symptoms?
XP-A and XP-C are characterized by early skin cancer and severe neurological complications. (Right if they mention one of the two)
What is the difference between a prenatal diagnosis and a prenatal screening? Hint: They both test for disorders in the fetus.
Prenatal diagnosis confirms whether the baby has a specific disorder (99% accuracy).
Prenatal screening assesses the statistical probability of a baby inheriting a disorder.
What is another name for Afamelanotide?
Scenesse
What is the main difference between xeroderma pigmentosum and other disorders?
Other genetic disorders are caused by missing enzymes or proteins, whereas XP has defects in genes that repair DNA.
Explain the development of skin cancer when a xeroderma pigmentosum patient is exposed to the sun (UV radiation). (3 steps)
UV radiation is transferred to DNA, causing mutations. -> Since the NER system is impaired, it cannot detect damaged DNA -> The cell with the damaged DNA keeps reproducing, making it cancerous.
Besides natural sunlight, which common everyday object emits enough UV radiation to trigger these symptoms indoors?
A) Television screens
B) Fluorescent light bulbs
C) LED light bulbs
D) Standard Wi-Fi routers
Fluorescent light bulbs emit a large amount of UV radiation.
This prenatal diagnosis is done during pregnancy by performing a needle-based fluid extraction procedure.
(Chorionic Villus Sampling or Amniocentesis)
Amniocentesis is a medical procedure that uses a needle to extract a small sample of amniotic fluid from the sac surrounding a fetus to test for genetic conditions.
What is Ex Vivo Skin Grafting?
Taking a patient's skin cells or tissue, modifying them to have a normal DNA sequence in a laboratory, and then transplanting them back to the patient.
Does xeroderma pigmentosum mean that a person's DNA is more easily damaged by UV light or that their cells are bad at repairing the damage afterward?
Their cells are bad at repairing the damage.