Genetic & hereditary disorders

[Kumar]

Hello all,

Can you pls tell me the followings:-

1. Can a developing foetus get some genetic or hereditary defects during gestation period in the form of some common disorders like diabetes, HBP etc. (which a mother can also experiance as pregnancy complication like gest. diabetes)?

2. If the above is possible then: can it be a structural damge, a mutation in few basic cell's nuclear or mitochondrial DNA which may multiply later on?

If we study Gest. Diabetes http://www.diabetes.org/gestational-diabetes.jsp, we may see that it can effect child.

Best wishes.

 

[spuriousmonkey]

1. Can a developing foetus get some genetic or hereditary defects during gestation period in the form of some common disorders like diabetes, HBP etc.

My view on this matter:

Anyone can acquire a hereditary disorder at any point in its life and therefore also the developing fetus can do so. However, for it to be hereditary the mutation has to occur in the germline. Hence the individual that acquired the mutation will not show the disease, unless the mutation happened to occur at an extremely early stage, for instance the fertilized oocyte. Since obviously this cell will give rise to all cells in the embryo, both somatic and germ line cells.

 

[Kumar]

Thanks. But some other pregnancy induced/related complications which comes during later stages of pregnancy also leaves some birth defects in baby. Why then imbalanced blood sugar due to gest. diabetes which presents somewhat insulin resistance type condition in mother & which also causes high blood sugar in foetus--can't leave birth defect as modren diabetes?

 

[spuriousmonkey]

Thanks. But some other pregnancy induced/related complications which comes during later stages of pregnancy also leaves some birth defects in baby. Why then imbalanced blood sugar due to gest. diabetes which presents somewhat insulin resistance type condition in mother & which also causes high blood sugar in foetus--can't leave birth defect as modren diabetes?

You were talking about hereditary diseases first. This is something else.

 

[Kumar]

That is the thought only. Can't modren diabetes cases be a birth defect caused by GD some damage to pancreas, wheras it is taken as genetic/hereditary disease?

 

[Kumar]

My view on this matter:

Anyone can acquire a hereditary disorder at any point in its life and therefore also the developing fetus can do so. However, for it to be hereditary the mutation has to occur in the germline. Hence the individual that acquired the mutation will not show the disease, unless the mutation happened to occur at an extremely early stage, for instance the fertilized oocyte. Since obviously this cell will give rise to all cells in the embryo, both somatic and germ line cells.

Can't mutations(influenced by mother's pre-disposition to disease) in few cells(not in all) already multiplied from fertilized oocyte at very early stages be possible?

Are we very very sure technically that true genetic/hereditary diseases with defective mutations in genome can present symptoms late in life???How as all part are already developed at birth & mutations should also be there in all cells?

 

[spuriousmonkey]

Can't mutations(influenced by mother's pre-diposition to disease) in few cells(not in all) already multiplied from fertilized oocyte at very early stages be possible?

i didn't quite get this. Can you rephrase?

 

[Kumar]

Can't mutations(influenced by mother's pre-disposition to disease) in few cells(not in all) already multiplied from fertilized oocyte at very early stages be possible?

Added: Are we very very sure technically that true genetic/hereditary diseases with defective mutations in genome can present symptoms late in life???How as all part are already developed at birth & mutations should also be there in all cells?

I want to know that if some mutations in just few cells of already developed foetus/embryo, influenced/transffered by mother's pre disposition to any disease eg.GD,HBP etc. is possible or not, which may lead to modren diseases? In short, can the so called G/H diabetes be only maternal post-fertilization?

 

[Kumar]

i didn't quite get this. Can you rephrase?

I got this interesting & most relevant link to this subject:-

..It is now clear that in many cases the fetus is more sensitive than the adult to the same environmental insults. Exposure to environmental agents during early development can result in death, structural malformation, and/or functional alteration of the embryo or fetus. These toxicant-induced pathogenic responses are most likely the result of altered gene expression associated with altered cell production and cell differentiation involved in the establishment of cell lineages leading to the structural and functional character of the tissues, organs, and systems that arise from these lineages...
...In support of the Barker hypothesis, epidemiologic studies have shown that markers of malnutrition, such as low birth weight, small for gestational age, or frank intrauterine growth retardation (IUGR) strongly predict the subsequent occurrence of hypertension, hyperlipidemia, insulin resistance, type 2 diabetes mellitus, ischemic heart disease, breast cancer, and prostate cancer in adult life. Fetuses that are clinically malnourished during the first trimester of development are three times more likely to be obese as adults. In addition to malnutrition, environmental exposures present during in utero development can have profound influences on fetal growth...
http://ehp.niehs.nih.gov/docs/2003/111-10/fga.html

However I am bit un-clear from this link on "whether these toxicant-induced pathogenic responses are most likely the result of altered gene" are genome based or pregnancy based.

Anyway if it means that our genes are just weakened during pregnancy not inherited from genome in typeII diabetes & Insulin resistance cases, Does it mean that modern environmental factors & lifestyle are only responsible factors to typeII diabetes? Suppose, if we change/correct the modern environment & lifestyle--will it correct this diabetes( as car if again brought to sea level)? Will the exposure of this modern environmental factors & lifestyle, add the weakness to the already weakened genes & so will make them more suspectible in next generation?

However if nuclear genes of genomes are involved in this type inspite weakened or mutated, still genetic role/passing is equally involved. Does it look technically correct that such a high outbreak of typeII diabetes in current generation can be genetic passing(of weakened genes) in consideration of natural selections, low probability, body's power to repair damaged genes, only one or two generations are involved in current out-break or otherwise?

 

[spuriousmonkey]

like I said many times before, if a disease is to become hereditary the mutation must be present in the germline. Once it is there it is bound to stay there forever untill it is selected out (failure to reproduce in all individuals that have the mutation).

 

[Kumar]

Then, in view of my previous posting, typeII diabetes, insulin resistence, high blood pressure etc. so aquired during pregnany--can not be hereditary or genetic diseases. Is it ok? Can we take it that these diseases are at all not hereditary/genetic?

 

[spuriousmonkey]

Then, in view of my previous posting, typeII diabetes, insulin resistence, high blood pressure etc. so aquired during pregnany--can not be hereditary or genetic diseases. Is it ok? Can we take it that these diseases are at all not hereditary/genetic?

No.

 

[Kumar]

How these diseases, then can be hereditary/genetic?

 

[spuriousmonkey]

Let me answer that by asking a question:

why couldn't they be heriditary?

The diseases you mention can have many causes. Sometimes they are hereditart, sometimes they are environmental, sometimes a mixture.

But all this doesn't mean that an environmental induced disease can cross simply into the germline to become hereditary.

 

[Kumar]

I doubt it as hereditary, in considration of their high magnitude in modren times, mostly typeII with IR. Are modern/recent types of these diseases not somewhat differant then the old classical genetic types? Are this environmentally induced diseases factors mentioned in any medical informations provided on various reputed sites as of ADA,medline etc.? Anyhow, I repeat my previous question:-

"Are we very very sure technically that true genetic/hereditary diseases with defective mutations in genome can present symptoms late in life???How as all part are already developed at birth & mutations should also be there in all cells?"

 

[Kumar]

It is now widely accepted that the risks of a number of chronic diseases in adulthood may have their origins before birth. Such diseases include non insulin-dependent diabetes mellitus, hypertension and coronary heart disease. Professor David Barker and colleagues in Southampton have produced a large proportion of the data in this field over the last decade...http://ije.oupjournals.org/cgi/content/full/30/1/15

More detailed information in this article.

 

[spuriousmonkey]

that doesn't contradict this statement:


But all this doesn't mean that an environmental induced disease can cross simply into the germline to become hereditary.

 

[Kumar]

that doesn't contradict this statement:


But all this doesn't mean that an environmental induced disease can cross simply into the germline to become hereditary.

Yes, it is true, I therefore doubt modern diseases(typeII diabetes, IR...) as hereditary.

Can you awnser this question:-

"Are we very very sure technically that true genetic/hereditary diseases with defective mutations in genome can present symptoms late in life???How as all part are already developed at birth & mutations should also be there in all cells?"

 

[Kumar]

Fetal, Infant, and Childhood Growth Are Predictors of Coronary Heart Disease, Diabetes, and Hypertension in Adult Men and Women
http://ehp.niehs.nih.gov/members/2000/suppl-3/545-553osmond/osmond-full.html#diab

However these abstracts are also very much indicative but I have some doubt in this:-

However, whereas insulin resistance was associated with low birth weight, noninsulin-dependent diabetes was associated with shortness at birth in relation to birth weight (i.e., a high ponderal index) and with maternal adiposity.

 

[Kumar]

Autoimmune Disease and the Environment
Almost all autoimmune diseases occur more often in women than in men; in some of these diseases, more than 90% of patients are female. It is not clear exactly why women are targeted more often than men, but estrogen is suspected to play a pivotal role. Autoimmune diseases seem to particularly attack connective tissue and the neuromuscular, endocrine, and gastrointestinal systems, but are not unknown in other parts of the body.
http://ehp.niehs.nih.gov/docs/1998/106-12/niehsnews.html#auto

It is relevant. We may need it as a future referance.