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Where exactly is adrenoleukodystrophy on the x chromosome?
The specific location of the mutation that causes X-ALD is on the ABCD1 gene on the X-chromosome. Please note that there isn't a specific mutation in the ABCD1 gene that causes X-ALD or can be related in any way to the different clinical presentations of the disease.
What is X-linked Adrenoleukodystrophy causes by?
X-linked Adrenoleukodystrophy is caused by mutations in the ABCD1 gene, which leads to a deficiency in the ALD protein. This protein is essential for the breakdown of very long-chain fatty acids. The accumulation of these fatty acids in tissues such as the adrenal glands and the white matter of the brain results in the symptoms of the disorder.
Do boys or girls get ALD?
Boys unlike girls, have only one x gene. They are more likely to get a recessive gene than a girl who has two x genes. Although it happens mostly in men, girls rarely, and I mean rarely get Ald.
Adrenoleukodystrophy?
DefinitionAdrenoleukodystrophy describes several closely related inherited disorders that disrupt the breakdown (metabolism) of certain fats (very-long-chain fatty acids).Alternative NamesAdrenoleukodystrophy; Adrenomyeloneuropathy; Childhood cerebral adrenoleukodystrophy; ALD; Schilder-Addison ComplexCauses, incidence, and risk factorsAdrenoleukodystrophy is passed down from parents to their children as an X-linked genetic trait. It therefore affects mostly males, although some women who are carriers can have milder forms of the disease. It affects approximately 1 in 20,000 people from all races.The condition results in the buildup of very-long-chain fatty acids in the nervous system, adrenal gland, and testes, which disrupts normal activity. There are three major categories of disease:Childhood cerebral form -- appears in mid-childhood (at ages 4 - 8)Adrenomyelopathy -- occurs in men in their 20s or later in lifeImpaired adrenal gland function (called Addison disease or Addison-like phenotype) -- adrenal gland does not produce enough steroid hormonesSymptomsChildhood cerebral type:Changes in muscle tone, especially muscle spasms and spasticityCrossed eyes(strabismus)Decreased understanding of verbal communication (aphasia)Deterioration of handwritingDifficulty at schoolDifficulty understanding spoken materialHearing lossHyperactivityWorsening nervous system deterioration ComaDecreased fine motor controlParalysisSeizuresSwallowing difficultiesVisual impairment or blindnessAdrenomyelopathy:Difficulty controlling urinationPossible worsening muscle weakness or leg stiffnessProblems with thinking speed and visual memoryAdrenal gland failure (Addison type):ComaDecreased appetiteIncreased skin color (pigmentation)Loss of weight, muscle mass (wasting)Muscle weaknessVomitingSigns and testsBlood levelsChromosome study to look for changes (mutations) in the ABCD1 geneMRI of the headTreatmentAdrenal dysfunction is treated with steroids (such as cortisol).A specific treatment for X-linked adrenoleukodystrophy is not available, but eating a diet low in very-long-chain fatty acids and taking special oils can lower the blood levels of very-long-chain fatty acids.These oils are called Lorenzo's oil, after the son of the family who discovered the treatment. This treatment is being tested for X-linked adrenoleukodystrophy, but it does not cure the disease and may not help all patients.Bone marrow transplant is also being tested as an experimental treatment.Expectations (prognosis)The childhood form of X-linked adrenoleukodystrophy is a progressive disease that leads to a long-term coma (vegetative state) about 2 years after neurological symptoms develop. The child can live in this condition for as long as 10 years until death occurs.The other forms of this disease are milder.ComplicationsAdrenal crisisVegetative state (long-term coma)Calling your health care providerCall your health care provider if:Your child develops symptoms of X-linked adrenoleukodystrophyYour child has X-linked adrenoleukodystrophy and is getting worsePreventionGenetic counseling is recommended for prospective parents with a family history of X-linked adrenoleukodystrophy. Female carriers can be diagnosed 85% of the time using a very-long-chain fatty acid test and a DNA probe study done by specialized laboratories.Prenatal diagnosis of X-linked adrenoleukodystrophy is also available. It is done by evaluating cells from chorionic villus samplingor amniocentesis.ReferencesJohnston MV. Neurodegenerative disorders of childhood. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 599.
Popquiz about current?
(Current-7)Current flows through a light bulb. Suppose a wire is connected across the bulb as shown. When this wire is connected...A: All the current continues to flow through the bulbB: Half the current flows through the bulb, half through the wireC: All the current flows through the wire.(Current-5)US Bulbs are rated for 120 V. European bulbs are designed for 240 V.If you buy a 100 W light bulb as a souvenir in Paris, and plug it in at home, what happens?A: It glows as usual, like a 100 W bulb should.B: Bzzzt, it burns out, too much powerC: It glows half as bright (powerful) as usualD: It glows 1/4 as bright as usualE: None of these/not enough info/don't know.(Current hmy-1)Electric companies generally tell their power customers the # of kilowatt-hours consumed in a month.What quantity is the power company telling you?A: power, duh!B: energy / timeC: timeD: energyE: None of these/impossible to determineF: current(Current_hmy-04)Rank in order, from largest to smallest, the powers dissipated in resistors a to d.R, DV+-R, 2DV+-2R, DV+-½ R, DV+-abcd1. a , b, c, d2. b, d, a, c3. b, c, a=d4. a=d, c, b5. b, d, b, c(Circuits-01)A battery with voltage ("emf") of 5V is attached to a resistor of resistance R. The circuit diagram is shown below. The point A is at zero volts.I) The correct voltages at the points B, C, and D are:A: VB = 0, VC = 5, VD = 0B: VB = 5, VC < 5, VD> 0C: VB = 5, VC < 5, VD= 0D: VB = 5, VC = 5, VD=0E: None of these.II) Which way does the current flow in this circuit?A: ClockwiseB: CounterclockwiseC: Not enough information given(Circuits-06)I) What is the "equivalent resistance" of this circuit?A: 1 WB: 2 WC: 3 WD: 4 WE: None/???II) What is the current flowing through resistor R2?A: 1.5 AB: 2 AC: 3 AD: 4 AE: 12 A(Circuits-07)I) What is the "equivalent resistance" of this circuit?A: 1 W B: 2 WC: 3 WD: 4 WE: None/???II) What is the current flowing through resistor R4?A: 1.5 AB: 2 AC: 4 AD: 6 AE: 12 A(Circuits-08)A circuit is built with two different resistors in series, as shown.I) What can you say about the current flowing past points A and C?A: IA = ICB: IA > ICC: IA < ICD: Not enough info.II) What can you say about the voltage drop across resistor R1 (i.e. VA-VB), compared to the voltage drop across resistor R2 ( i.e. VB-VC)A: (VA-VB) = (VB-VC ) = 5 VB: (VA-VB) = (VB-VC ) = 2.5 VC: (VA-VB) > (VB-VC)D: (VA-VB) < (VB-VC)E: Not enough info.(Circuits-09)A circuit is built with two resistors in parallel, as shown.I) What can you say about the current flowing past points A and B?A: IA = IBB: IA > IBC: IA < IBD: Not enough info.II) What can you say about the voltage drop across resistor R1 (i.e. VA-VC), compared to the voltage drop across resistor R2 ( i.e. VB-VD)A: (VA-VC) = (VB-VD ) = 5 VB: (VA-VC) = (VB-VD ) = 2.5 VC: (VA-VC) > (VB-VD)D: (VA-VC) < (VB-VD)E: Not enough info.
