Germline mutations are more harmful than mutations in somatic cells?

[FTM1000]

Sorry if my question contain misconceptions, I am just trying to learn biology on my own.
From what I understood, every cell contain the same DNA and different cells express/use different parts of that DNA according to whether they are blood cells, skin cells, muscles cells etc. And cells get mutations in their DNA, including the parts they don't use/express, right?. So when a somatic cell get a mutation on a gene it doesn't use can it have an impact on the cell?. And what about mutations in germline cells?, if a germline cell have a mutation that mutation will end up in the cells of the baby and at least one type of the baby's cells will express the mutated gene and the mutation can have an impact on the baby. am I right?.
So a mutation on germ cell have more chance of causing harm to the baby than the chance of the same mutation on somatic cell (that doesn't express the mutated gene) to cause harm to a person?.

 

[BillTre]

Mutations can kill or not kill the cells they are in, depending on the details of the mutation and the cell.
Mutations in somatic cells can have a relatively quick negative effect on an organism, possibly including death. Cancer is due to somatic mutations in the cells that are cancerous.
Mutations in germline cells may not kill the germline cells immediately, but could have negative effects on an offspring generated from a germline cell carrying a mutation. The mutation would be inherited by all the somatic cells of the new offspring and could affect any of the cell types the particular mutation might be able to affect.

 

[FTM1000]

Mutations can kill or not kill the cells they are in, depending on the details of the mutation and the cell.
Mutations in somatic cells can have a relatively quick negative effect on an organism, possibly including death. Cancer is due to somatic mutations in the cells that are cancerous.
Mutations in germline cells may not kill the germline cells immediately, but could have negative effects on an offspring generated from a germline cell carrying a mutation. The mutation would be inherited by all the somatic cells of the new offspring and could affect any of the cell types the particular mutation might be able to affect.

But am I right about what I said earlier? or I just misunderstood something?.

 

[Drakkith]

So when a somatic cell get a mutation on a gene it doesn't use can it have an impact on the cell?

Yes, it's possible for the mutation to have an effect. For example, if the mutation changes the base pairs in such a way as to form a start codon, then the cell can accidentally translate and produce proteins from the wrong portion of the DNA molecule. This can have any number of effects on the cell, from barely noticeable all the way up to cell death.

And what about mutations in germline cells?, if a germline cell have a mutation that mutation will end up in the cells of the baby and at least one type of the baby's cells will express the mutated gene and the mutation can have an impact on the baby. am I right?.

It's possible. It depends on the exact mutation and its location. Some mutations are simply neutral. Some are negative, and some are positive depending on the interaction of the organism with its environment.

So a mutation on germ cell have more chance of causing harm to the baby than the chance of the same mutation on somatic cell (that doesn't express the mutated gene) to cause harm to a person?.

Generally, yes, because, as you said, a mutation in the germline would be passed on to every cell in the offspring. So a mutation that degrades ATP production would harm only a single somatic cell, whereas in germline cells it can cause systemic, chronic, and potentially lethal birth defects in offspring.