Two copies of the abnormal gene get passed down to cause conditions. Tay Sachs, common to Jewish populations, is one of these. It causes degeneration of the nervous system.
Tay Sachs Disease
One example of a nervous system breakdown caused by an autosomal recessive allele is spinal muscular atrophy (SMA). SMA is a genetic disorder that leads to the loss of motor neurons in the spinal cord, resulting in muscle weakness and atrophy. It is caused by mutations in the SMN1 gene on chromosome 5.
Trisomey-21
Turner syndrome is not autosomal; rather, it is caused by a complete or partial absence of one of the X chromosomes in females, resulting in a monosomy (45,X). This chromosomal condition can lead to various physical and developmental features, such as short stature and infertility.
The gene pair is referred to as homozygous recessive. This means that both copies of the gene are recessive, resulting in the expression of the recessive trait.
It sounds like you are describing a condition called degenerative disc disease. This condition occurs when the intervertebral discs in the spine deteriorate over time, often resulting in pain and reduced mobility. Factors such as trauma or strain can exacerbate the degeneration process. Physical therapy, pain management, and sometimes surgery may be recommended for treatment.
Codominance is a condition in which neither of two alleles of a gene is dominant or recessive. In codominance, both alleles are expressed in the phenotype of the heterozygote, resulting in a unique phenotype that is a mixture of the two alleles.
A homozygous genotype with both alleles being recessive is called a homozygous recessive genotype. This means that both copies of the gene are the same recessive allele, resulting in the expression of the recessive trait.
Homozygous dominant individuals have two identical dominant alleles for a particular gene, resulting in the expression of the dominant trait. Homozygous recessive individuals have two identical recessive alleles, resulting in the expression of the recessive trait.
emphysema (C)
emphysema (C)
The brain shows a remarkable degree of degeneration with age, resulting in cognitive decline and memory loss. This can lead to conditions such as dementia and Alzheimer's disease. Regular mental exercise and a healthy lifestyle can help slow down this degeneration.