Question

Write a brief note on - Down syndrome.

Answer 1

Down’s Syndrome caused due to the presence of an additional copy of chromosome 21 (Trisomy of 21)
Here in this genetic disorder the affected individual has short stature, small, round head, furrowed tongue, partially opened mouth, palm crease, congenital heart disease and mental retardation.
                                                or It is a disease caused due to genetic disorder which occurs due to the presence of part or all of a third copy of the chromosome.
Its also known as trisomy 21. A person suffering from down syndrome could be recognized by his/her neck webbed, bulging eyes, tongue protruding out, mental retardation, short stature, mongoloid face and short lifespan.   

Answer 2

Dear Student,

In humans, there are total 46 chromosomes. Any deviation from this results in aneuploidy.

● Down syndrome -

• Down's syndrome is caused by non-dysjuction of chromosomes during meiosis.
• Karyotype of Downs syndrome is usually trisommy 21.

# Clinical features -

• mental retardation
• webbing of neck
• flat facies
• upward slant to eye
• congenital defects
• dwarfism
• simian course
• infertility
• abnormal ears
• Brushfield spots

# Diagnosis -

• Down's syndrome can be diagnosed prenatally by karto-typing.

Thanks dear. Hope this helps you...