Essential Interactive Image

Immediate FamilyHitchhiker's Thumb Pedigree

III

II

Trait Description

Analysis

My Future Child

Back

Next

If my husband can move his thumb back...

If my husband can not bend his thumb back...

For this example, I'll say I'm Homozygeous Dominant

MY FUTURE CHILD

Back

For this example, I am heterozygous

MY FUTURE CHILD PT. 2

Phenotype: Hitchhikers Thumb

Possible Genotypes: Homozygous Dominant (SS) or Heterozygous (Ss)

Grandfather

Tommy Thompson

Genotype: Homozygous Recessive (ss) Phenotype: Straight thumb

Grandmother

Yolanda Thompson

Genotype: Heterozygous (Ss) Her daughter does not have one which means she is heterozygous Phenotype: Hitchhikers Thumb

Aunt

Yolande Hanono

Possible Genotype: Homozygous Dominant (SS) or Heterozygous (Ss) Phenotype: Hitchhikers Thumb

Father

Tommy Thompson

Possible Genotype: Homozygous Dominant (SS) or Heterozygous (Ss) Phenotype:Hitchhikers Thumb

Mother

Sheri Hall

Possible Genotype: Homozygous Dominant (SS) or Heterozygous (Ss) Phenotype: Hitchhikers Thumb

Grandfather

Herold Henderson

Possible Genotype: Homozygous Domiant (SS) or Heterozygous (Ss) Phenotype: Hitchhikers Thumb

Grandmother

Suzanne Land

Possible Genotype: Homozygous Dominant (SS) or Heterozygous (Ss) Phenotype: Hitchikers Thumb

Aunt

Debbie Henderson

Possible Genotype: Homozygous Dominant (SS) or Heterozygous Phenotype: Hitchhikers Thumb

Uncle

Brian Henderson

Possible Genotype: Homozygous Dominant (SS) or Heterozygous (Ss) Phenotype: Hitchhikers Thumb

Brother

Tommy Thompson

Possible Genotype: Homozygous Dominant (SS) or Heterozygous (Ss) Phenotype: Hitchhikers Thumb

Me!

Laura Thompson

Hitchhikers thumb is a genetic trait related to the flexibility of the thumb joint. Some have a straight thumb while others can bend their thumb back at the joint. This gene is controlled by a single gene with two alleles. The dominant allele gives you a straight thumb, while the recessive allele allows you to move it back. For genotypes, there can be either homozygous dominant (SS) where both alleles are dominant and result in a straight thumb, Heterozygous (Ss) still leading to the straight thumb because of the dominant allele, or you could have homozygous recessive (ss) where both alleles are recessive leading to a hitchhikers thumb. The two phenotypes are straight thumb (through homozygous dominant or heterozygous) or hitchhikers thumb from homozygous recessive. As for the traits inheritance pattern, it follows Mendelian autosomal. Autosomal refers to the chromosomes that don’t determine an individuals sex. Genetic modifiers or environmental factors could play a role in this trait as well. I chose this trait because I did not even know that some people could not move their thumb back like I could. This fascinated me and I wanted to see who else could do it in my family.

Almost my entire family had the trait. This means that almost all my family is either homozygous dominant or heterozygous. It is more likely that we are homozygous dominant than all heterozygous because atleast one of us would have been recessive.I got the trait from my mom and my dad. This gene is autosomal so it gets passed on through chromosomes. My cousin for example, her mom had the trait but she didn't this means that my aunt has to be heterozygous and got the none dominant allele from my grandma. This also means my cousins dad has to either be homozygous recessive or heterozygous aswell.