down syndrome

[Ehsan Alirahimi]

Hello,

 

Does any one know why people with down syndrome in the world show thesame (not exact) phenotype (such as underdeveloped teeth and foul-smelling urine ).

 

many thanks in advance.

 

 

[tomgwyther]

I found some information here on the teeth thing:

 

Teeth

 

the foul smelling urine could be down to 'Trimethylaminuria' ; A genetic condition

[bbouch111]

They all have some of those same phenotype(s) that you mentioned because they all have the same genetic mutation. Like a red-headed person, they have the same type of mutation. Down syndrome is caused by trisomy 21 which is an extra genetic material on the 21st chromosome.

[Psycho]

They all have some of those same phenotype(s) that you mentioned because they all have the same genetic mutation. Like a red-headed person, they have the same type of mutation. Down syndrome is caused by trisomy 21 which is an extra genetic material on the 21st chromosome.

Down syndrome isn't caused by a genetic mutation. It is caused by incorrect segregation of chromosomes in meiosis.

[Lukas!]

You could also see Down from something called a Robertsonian translocation. In this case, when the meiocytes divide, some chromosomes are "part 21" and "part 14". If the gamete split leaves one with the Robertsonian 14-21 combination AND the normal 21, upon fertilization the zygote will have 3 copies of 21 INFORMATION, thus resulting in Down syndrome.

[technie]

Are they related, down syndrome is a genetic disorder, known as trisomy 21, having 3 chromosomes on the supposed 21st pair, an error when chromosomes are lined up on the spindle apparatus in meiosis. But are the teeth and urine problems genetic in nature?