Muscular dystrophy certain types is sexlinked Unfortunately

Muscular dystrophy (certain types) is sex-linked. Unfortunately, most males die by age 17. Show, through Punnett squares, how females do not get this disorder.

Solution

Muscular dystrophy -= x- linked recessive disorder .

Duchenne muscular dystrophy i--------- inherited in an X-linked recessive pattern.

X-linked recessive pattern.

In male a single x – linked recessive allele is enough for expression.

Where as

In females required double dose of X-linked recessive allele are required

Genotype    X^mX -Normal heterozygous female

Gentype   XX -----normal homozygous female

Genotype   X^mX ^m--------affected female homozygous

Gentype   XY -----normal male

Genotype   X^mY--------affected male

X^mX -Normal heterozygous female X Gentype   XY -----normal male

X

Y

X^m

X X^m

Y X^m      AFFECTED

X

XX

YX

XX -Normal female X Gentype   X^m Y -----affected male

X^m

Y

X

X X^m         carrier normal

Y X normal

X

XX^m           carrier normal

YX        normal

X^mX^m -affected female X Gentype   XY -----normal male

X

Y

X^m

X X^m carrier normal

Y X^m      AFFECTED

X^m

X X^m carrier normal

Y X^m AFFECTED

	X	Y
Xm	X Xm	Y Xm      AFFECTED
X	XX	YX