Showing posts with label Genetics. Show all posts
Showing posts with label Genetics. Show all posts

Friday, May 12, 2017

Marfan syndrome - High Yield Information.

Hello everybody,
lets today briefly revise all the high yield points on Marfan syndrome.

Marfan syndrome is an example of structural protein disorder and with autosomal dominant inheritance, lets see what exactly goes wrong in this condition.


There is a missense mutation seen in the fibrillin-1 gene located on the chromosome no.15.
So to understand the condition better, lets understand a bit about fibrillin.

Fibrillin forms the glycoprotein component of cellular microfibrils and also provides a scaffold for the elastin deposition.
Abundant fibrillin is found in the connective tissues of the aorta,ligaments and the eye, these are the structures predominantly affected in the disorder too.

The defective fibrillin leads to defective microfibril assembly intracellularly and reduced elasticity in connective tissues.
 Defective fibrillin also leads to decreased TGF-beta(Transforming growth factor ) sequestration, and excess of TGF-B hampers normal vascular smooth muscle development and matrix production.

Morphological Features:

1) Skeletal changes:
    Tall stature with long extremities.
     Long tapering fingers and toes.(Arachnodactyly)
     Kyphosis ans scoliosis.
     Pectus excavatum or Pigeon breast deformity.

2) Cardiovascular changes:
     Aortic regurgitation: Due to aortic cystic medial degeneration leading to valvular ring dilatation & valvular incompetence. Most threatening valvular lesion.
     Mitral valve prolapse : Most common valvular lesion.
     Aortic Dissections are the most common cause of death in these patients.

3) Occular changes:
    Ectopia Lentis: bilateral superotemporal dislocation of lenses.
    Retinal Detachment : due to increased axial length of the globe.


Currently Revised Ghent Criteria is used for the diagnosis of Marfan syndrome.
It considers:
Family history,
Cardinal Clinical Signs in absence of family history,
Presence or absence of Fibrillin Mutation.

so that's all on marfans syndrome.

Fun Fact:
We all have been hearing about some famous personalities with Marfan syndrome like Abraham Lincon and Michael Phelps, but Tutankhamen the 11th pharoh of 18th Egyptian Dynasty was diagnosed to be suffering from Marfan's Syndrome by a series of CT scans and DNA tests carried out on his MUMMY!

Do post any other interesting facts you know about Marfan's Syndrome.

Let's Learn Together!

Wednesday, May 3, 2017

Initiation factors in eukaryotic translation mnemonic

Hello Everyone,

Lets discuss Initiation factors today. Here's the the mnemonic:

1. elF-1: 1 looks like i . So it causes Dissociation of 80 S

2. eLF-2: Two- Formation of Ternary complex. Also GTP needed

3. eLF-3: 3 looks like B. hence it causes Breakdown(dissociation of 80 S)

4. elF-4:   
cap binding protein complex elF-4F=  elF-4E + elF-4G+ elF-4A . Binds to 5’End of mRNA through elF-4E  
elF-4A and elF-4B: A has helicAse activity.Makes use of ATP 
                                B makes things Better. :)
                                Both help  reduce complex secondary structure of 5’end of m-RNA.                                                                                                           (A+B=reduce Complexity)

5. eLF-5: 5 looks like S. So it causes: 
      1. releaSe of initiation factors
      2. aSSociation of 40S and 80S Subunits

Here are some diagrams that will help you:

That’s all,
Thank you,
Chaitanya Inge

Tuesday, April 18, 2017

Sunday, April 16, 2017

Mnemonico diagnostico : Klinefelter's syndrome

Hey Awesomites

Criteria for diagnosis of Klinefelter's syndrome in males mnemonic : KLINEFELTER

K - (K) Cryptorchidism
L - Leydig cells hypertrophy
I - Increased gonadotrophins
N - Negative/ Positive chromatism (aberrations)
E - Elongated legs
F - Failure of secondary sexual characters
E - Eunuchoidism
L - Late pubic hair
T - Testicular failure
E - Erectile dysfunction / Elbow deformities
R - Retardation (mental)

Thats all
- Jaskunwar Singh

Monday, March 6, 2017

Fact of the day: Blood coagulopathies in Familial Hypercholesterolemia


It is known since long that familial hypercholesterolemia is associated with increased risk of cardiovascular disease as a consequence of atherosclerotic plaques in blood vessels. But Its NOT due  to high cholesterol levels in blood !!

The cause of such consequences lies in genetics. Genetic aberrations in patients with FH include variations in Prothrombin gene which increases coagulation and clot formation. This ultimately blocks the arteries by forming plaques!

Heart patients with FH also have higher concentrations of Fibrinogen and Factor VIII in their blood in addition to other factors, compared to healthy ones.

People with familial hypercholesterolemia tend to live a longer life than those with low cholesterol levels, suggesting a minor role of high cholesterol in pathogenesis of the disease.

However, cholesterol is still associated with other systemic diseases, though recently LDL has been considered 'good' too!

That's all
- Jaskunwar Singh

Friday, February 24, 2017

Saturday, February 18, 2017

Pierre Robin Sequence mnemonic

Hey Awesomites

Pierre Robin Sequence is one of the most common causes of isolated cleft palate in the newborns. Here's the mnemonic for the triad of symptoms- PRS

P- Cleft Palate only
R- Retrognathia (abnormal posterior position of jaw and maxilla)
S- Support to the lingual muscles is lost (Glossoptosis)

The sequence is known to be caused by genetic anomalies at chromosome 2, 11 or 17.

That's all

- Jaskunwar Singh

Sunday, January 29, 2017

Sunday, January 22, 2017

Klein waardenburg syndrome mnemonic

Here's a small post :)

Waardenburg syndrome is a rare genetic disorder most often characterized by varying degrees of deafness, minor defects in structures arising from the neural crest, and pigmentation changes.

Synonyms: Waardenburg Shah syndrome, Waardenburg-Klein syndrome.

Monday, January 16, 2017

Can virus kill cancer cells ?

Hello awesomites !Today's topic is short ,simple and easy to understand.

Cancer is basically a disease where there is abnormal growth of cells in body and sometimes it is also malignant that is ,it can spread from one organ/site to another.These newly formed cells can disturb normal cycle of other cells .When a  cell suffers DNA damage from cancer,a virus or radiation a group of protein complex MRN is sent to repair DNA.MRN is protein complex ,it consists of Mre11,
Rad50 and Nbs1 .In eukaryotes initial processing of double strand DNA breaks prior to repair by homologus recombination or by non-homologus joining.
When a DNA virus is present in the cell,MRN instead focuses on removing it.
If both DNA damage & a DNA virus are present in a single cell .The MRN complex is unable to manage both threats at once and ends up ignoring the virus .
These new findings imply that scientist might be able to form a virus that targets and  kills only cancer cells.

Keep smiling:)
Good day:)

Wednesday, December 28, 2016

Vogt's triad in tuberous sclerosis mnemonic

Vogt's triad in tuberous sclerosis mnemonic:
Epi- Epilepsy
Loi- Low IQ
As- Adenoma sebacum

- Jaskunwar Singh

Thursday, December 22, 2016

Crispy C.R.I.S.P.R.!

10 years ago,only a few would have thought that a device in our pockets would be good enough to access all the information of the world, would do social networking, calls, would calculate, act as a torch and what not. 

We today are on a similar brink ofrevolution in genetic engineering, where the effects would be so magnificent that they would need to be measured on a Richter scale! 

Enter CRISPR, which is an acronym for 'clustered regularly interspaced shortpalindromic repeats', a  crispy new technology which promises to shrink the costs involved in genetic engineering by 90%makes the procedure easier andshorter.

*What is it? 
We have managed to hack an antibacteriophage mechanism in bacteria to our advantage. 

Only a few bacteria survive bacteriophage invasion. To protect themselves from a further invasion, they store a part of the phage DNA into their archives. 

When another attack does occur, an RNA copy of the archived phage DNA is presented to what is known as a CAS 9 protein.

CAS 9 compares the two copies, one from the foreign DNA and the other from the archives, and is very precise at that. 

If it finds a 100% match, it cuts off thenew phage's DNA, thus rendering the attack a big embarrassment for the bacteriophage. :-p 

*What can we do with it? 
Oh, a lot of awesome things! 

-Pissing off viruses
In 2015, scientists armed with CRISPR achieved a significant reduction of HIV load from patiens. 
This year, in mice, they slashed off 51% HIV DNA from mice, just by a couple of shots in their tails! 

*Making cancer re evaluate its careerchoice
Malignant cell detection by the immune system can be enhanced. 

*Designer babies- 
A lot of desirable traits- super awesome eyesight, superman esque strength and so on, can be selected from a wide palette during embryogenesis.

*Bidding adieu to genetic diseases

*Making ourselves look hot at 120-

CRISPR holds the potential to slow and even reverse ageing! We can take a leaf off the books of certain aquatic species who already are doing that. 

.. and a lot more. 

*The last word
A few controversies sorround though.
- We don't know if any adverse 
  reactions may triggered, as our 
  knowledge is still just the tip of the
- Some powers like say dictators
   might use it to gain precedence.
- The fear of genetic pollution.

Anyway, these are just hurdles which we need to plan and overcome for a glorious future for humanity! 

Source- Kurzgesagt. 


Tuesday, December 20, 2016

Medipicsowesome: Adams Oliver syndrome

Hey everyone!

Hope you are enjoying Medipicsowesome!

Adams–Oliver syndrome (AOS) is a rare congenital disorder characterized by defects of the scalp and cranium (cutis aplasia congenita), transverse defects of the limbs, and mottling of the skin.

The baby has a defect in the frontal and parietal bone and terminal limb defects in the legs.

That's all!


Medipicsowesome: Thanatophoric dysplasia


First post of Medipicsowesome. Yaay!

Thanatophoric dysplasia (TD) is a lethal skeletal dysplasia. It is the 2nd most common lethal skeletal dysplasia after osteogenesis imperfecta type II.

It is characterized by extremely short limbs and folds of extra (redundant) skin on the arms and legs.

Other features of this condition include a narrow chest, short ribs, underdeveloped lungs, and an enlarged head with a large forehead and prominent, wide-spaced eyes.

Type I thanatophoric dysplasia is distinguished by the presence of curved thigh bones and flattened bones of the spine (platyspondyly).

Type II thanatophoric dysplasia is characterized by straight thigh bones and a moderate to severe skull abnormality called a cloverleaf skull.

This baby seems to have type II thanatophoric dysplasia.

The condition is uniformly fatal within a few hours of birth either from respiratory failure or from brainstem compression from a narrow foramen magnum.

This baby died a few hours after birth.

Cool fact: The term thanatophoric derives from the Greek words "thanatos" meaning "death" and "foros" meaning "bearing/carrying/bringing".

That's all!

Wednesday, December 14, 2016

A 7 year old with hyperextensible joints

A 7 year old boy is brought to you. He is intellectually disabled. On examination, you notice hyperextensible joints. Large hands, large feet, protruding ears, elongated face are also seen. The patients testes are large in size compared to his age. Diagnosis?

Marfans syndrome
Ehler Danlos syndrome
Fragile X syndrome
Friedreichs Ataxia

Answer below
It's Fragile X syndrome. Why isn't it's Marfans? Because Marfans has normal IQ.

Here are my notes + mnemonic for Fragile X syndrome.

Did you know?
Fragile X is the most common cause of inherited mental retardation.
It was the first trinucleotide repeat disorder to be recognized.

That's all!

Sunday, December 11, 2016

Friedreichs Ataxia notes and mnemonic

Here's another notes + mnemonic post on Friedreichs Ataxia

Genetic stuff:
- Due to mutated frataxin gene
- GAA trinucleotide repeats
- Autosomal recessive
- Mitochondrial iron accumulation due to loss of iron transporter coded by frataxin gene results in oxidized intramitochondrial iron accumulation.

Clinical stuff:
- Cardiomyopathy is the most common cause of death in FA. Cardiomegaly, conduction defects, murmurs, fibrosis are seen.
- Musculoskeletal abnormalities like foot deformities (Hammer toe, pes cavus, pes equinovarus) and scoliosis is seen.
- Diabetes mellitus is seen in 20% of patients

Neurologic stuff:
- Nystagmus
- Titubation
- Dysarthria
- Dysmetria
- Ataxia of trunk and limb movements.
- Loss of proprioception and vibratory sense.
- Extensor plantar response, absence of deep tendon reflexes and weakness is found.

That's all!

Mnemonic: Friedreichs FRIEDS! 

Saturday, December 10, 2016

Myotonic dystrophy notes and mnemonic


Here are my notes + a mnemonic

Congenital myotonic dystrophy
- Autosomal Dominant
- CTG trinucleotide repeat
- Genetic anticipation seen

- Hypotonia "floppy infant"
- Hollowing of temporal bones
- Tenting of upper lip
- Respiratory muscle weakness
- Arthrogryposis
- Posterior subcapsular cataracts (Subcapsular spokes in stellate conformation) 

Juvenile myotonic dystrophy

- Facial and upper body weakness (Hatchet face due to temporalis, masseter, facial muscle atrophy; frontal baldness)
- Inability to relax muscle (Sustained grip)

- Cardiomyopathy
- Heart block
- Congestive heart failure

- Intellectual impairment
- Gonadal atrophy
- Posterior subcapsular cataracts

- Thenar, hypothenar muscle atrophy (Myotonia evident on percussion)
- Tongue depression
- Dementia

That's all!
Be kind.

Sunday, December 4, 2016

What is the difference? : Meconium vs. Meconium Ileus

Hey Folks, Jay here!

Meconium is the very first stool ("poop") of a Neonate. This is mainly composed of the material that it ingested during its intrauterine life. This can include, amniotic fluid, mucus, bile, intestinal epithelium cells, lanugo and water.