The apparent mode of inheritance if Autosomal Dominant Inheritance: the reason if that, in the pedigree of this family only one copy of the HNPCC allele is present on male individual. There are 50% chances for HNPCC to occur on the male and female offspring of this male individual. All the diseased offspring has at least one parent carrying the dominant allele. We can also see that the transfer of HNPCC allele occurs from male to male. Colorectal cancer is affected by the age. Usually it occurs at the age of 50 years or above. But there have been cases where it was diagnosed at a very young age, as young as 31 years, just like in the given example. The reason behind such wide range of age is the inheritance of the disease. As the disease is inherited, the chances of it increase and thus it can be seen at a very young age. The risk of HNPCC increases two or three times with the family history in comparison to without the family history. Other factors that might affect the wide range are Environmental effect, diet and food habits. Solution The apparent mode of inheritance if Autosomal Dominant Inheritance: the reason if that, in the pedigree of this family only one copy of the HNPCC allele is present on male individual. There are 50% chances for HNPCC to occur on the male and female offspring of this male individual. All the diseased offspring has at least one parent carrying the dominant allele. We can also see that the transfer of HNPCC allele occurs from male to male. Colorectal cancer is affected by the age. Usually it occurs at the age of 50 years or above. But there have been cases where it was diagnosed at a very young age, as young as 31 years, just like in the given example. The reason behind such wide range of age is the inheritance of the disease. As the disease is inherited, the chances of it increase and thus it can be seen at a very young age. The risk of HNPCC increases two or three times with the family history in comparison to without the family history. Other factors that might affect the wide range are Environmental effect, diet and food habits..

1. The apparent mode of inheritance if Autosomal Dominant Inheritance: the reason if that, in the
pedigree of this family only one copy of the HNPCC allele is present on male individual. There
are 50% chances for HNPCC to occur on the male and female offspring of this male individual.
All the diseased offspring has at least one parent carrying the dominant allele. We can also see
that the transfer of HNPCC allele occurs from male to male.
Colorectal cancer is affected by the age. Usually it occurs at the age of 50 years or above. But
there have been cases where it was diagnosed at a very young age, as young as 31 years, just like
in the given example. The reason behind such wide range of age is the inheritance of the disease.
As the disease is inherited, the chances of it increase and thus it can be seen at a very young age.
The risk of HNPCC increases two or three times with the family history in comparison to
without the family history. Other factors that might affect the wide range are Environmental
effect, diet and food habits.
Solution
The apparent mode of inheritance if Autosomal Dominant Inheritance: the reason if that, in the
pedigree of this family only one copy of the HNPCC allele is present on male individual. There
are 50% chances for HNPCC to occur on the male and female offspring of this male individual.
All the diseased offspring has at least one parent carrying the dominant allele. We can also see
that the transfer of HNPCC allele occurs from male to male.
Colorectal cancer is affected by the age. Usually it occurs at the age of 50 years or above. But
there have been cases where it was diagnosed at a very young age, as young as 31 years, just like
in the given example. The reason behind such wide range of age is the inheritance of the disease.
As the disease is inherited, the chances of it increase and thus it can be seen at a very young age.
The risk of HNPCC increases two or three times with the family history in comparison to
without the family history. Other factors that might affect the wide range are Environmental
effect, diet and food habits.