Question

QUESTION 9 5 pe If the characteristic depicted in the pedigree below is rare and subject to complete penetrance, it is likely to be X-linked recessive? 5 6 7 -OOO No, because individuals ll-2 and 11-4 are not affected No, because individuals 111-4 and III-6 are not affected Yes, because individuals III-4 and III-6 are not affected Yes, because only females are affected in generation 11

Answer 1

Question 9

This question based on pedigree analysis to answer this question first lets understand the basic concept

# Pedosee analysis :- N X - No XP = Diseased ANNemo AD = Diseaser Normal Male comal Autosomal linked on Dominant Recessive Dominance Norma ANAN ANAN Malle ANAP Carre) Nomad femal x link Rcessive x Nu x Ny сүм XNXN ???? ocho xD ccarries)

ABAD ANAC? APAP Affected male ADAD AAP X XD C D Affected female ANAD yo po x xN Move - generahan I Marriage t o generahan I Number from I a 1 2 3 4

> To find desorder Recessue Dominant - . Skipping of genearon than disorder Cannot be dominant (assuming full Penetration) Generation not skipped can be dominant of can be recessive. at I gener nowe Dise I 2 3 TL Dise Generation not skipped Dominant of Recessive

In the given pedigree in question it is not x linked recessive disease because if female suffered from x linked disease his father and son must suffer from the disease

Generation skipped SS Recessive not dominant Generation skipped Recessive Autosoma Recessive X linked Recessive = Mostly only males are affected > Jf female diseased xdxd father must be diseased af not & hes progeny male child will be diseased No Generation skip but also can be recessive n Dominant Autosomal dominant ! x linked Dominant If male xly is diseared his mother must be diseased & his progeny female child must be diseased

But Individual 4 and 6 of generation 3 is not affected while their mothers are affected

Hence option 2 statement is correct reason for this to not be x linked disease

Answer is option2