For people carrying mutations that cause pheo, the risk of having children with the same mutation is 50%. The decision on whether to have children is ultimately a personal decision, and is largely influenced by people's own experience with the mutations. Most people with pheo-causing mutations do decide to have children and are happy with their decisions. Some of my patients choose not to have children because they feel the burden on the children and themselves would be too big.
Some patients wonder if these mutations can be diagnosed before implantation or in early pregnancy. This is a complicated ethical issue. The technology is certainly available. Since the mutations are already known in most cases, finding the mutation is present or not is straightforward. If the mutation is found, to discard a fertilized egg or terminate an early pregnancy means very differently to different people, and extreme views exist. All the genetic syndromes that have pheo as a component are usually not very bad, and people with these syndromes can have very productive life, making the prenatal diagnosis controversial.
Currently these prenatal diagnostics are not offered to most people. If you have a very negative experience with a genetic pheo syndrome and desire to have children without it, you may want to talk with your doctor to see if it is possible to do a prenatal diagnosis.
Dr. Pheo
Subscribe to:
Post Comments (Atom)
When I was diagnosed with metastatic pheo and found out that I also had the SDHB genetic mutation, I struggled greatly with the decision of whether or not to have children. But then one of my tumors in my abdomen required radiating right through my ovaries to get to it, so that decision was taken away from me and is no longer even a remote possibility.
ReplyDeleteDear Jorie,
ReplyDeleteThank you for sharing. In your case, it was potentially possible to freeze some eggs before the radiation therapy. I wonder if your doctor discussed this possibility with you.
Dr. Pheo
Dear Dr Pheo,
ReplyDeleteIn your article about hyperplasia, you mention that "MIBG scan typically is borderline positive".
I wonder if you had cases where I-123 MIBG scan had Grade 3 uptake (more intense than the liver) and surgery revealed a completely normal adrenal gland and did not help normalise BP?
(I posted my test results in your January page by mistake.)
Thank you.
Dear sersem,
ReplyDeleteI have not seen myself a false positive grade 3 uptake but I did see very bright grade 2 (close to grade 3) uptake that was false positive. The most important thing about pheo diagnosis is that a biochemical diagnosis has to be made unequivocally first. CT/MRI and MIBG are used to locate the tumor. I will write about the utility of MIBG scan in the next few months.
Dr. Pheo
Dear sersem,
ReplyDeleteI just read your full post under adrenal hyperplasia. Based on your description, it is unlikely for you to have pheo. There are many pheo mimickers and I suggest that you discuss with your doctors about alternative diagnoses.
Dr. Pheo
Dear Dr Pheo,
ReplyDeleteMany thanks for your prompt reply. I certainly wouldn't want to lose a serviceable adrenal gland with just the suspicion that it has a pheo.
Your article on MIBG scans will be much appreciated. I am particularly interested in your opinion as to when an intense focal uptake on only one adrenal gland is a false positive and when it could point to the formative stages of pheo.
There are many references for the latter case, one of which states: "Like others (45), we have encountered eight cases with only microscopic PCCs with almost normal catecholamine secretion levels that showed grade 3 [123I]MIBG uptake." (http://jcem.endojournals.org/cgi/content/full/86/2/685)
Thanks again for your help.
Dear Dr Pheo,
ReplyDeleteI'd like to comment on your suggestion to discuss alternative diagnoses with my doctors (in the last 3 years, my doctor count exceeded 10 & most of them I was required to attend in order to keep my job in aviation, which required adequate BP control -I have now lost my job as a result of the lack of diagnosis & successful treatment).
The closest I got to alternative diagnoses were: "sympathetic hyperreactivity" (based on exagerated HR responses to small postural changes & excessive sweating) and "autonomic dysfunction" (based on a tilt table test, where I had a vasovagal response to Isoprenaline but where my cardiovascular responses didn't quite reach IST or POTS limits).
I wonder if these really constitute diagnoses per se or are they alternative ways of stating my symptoms (ie that my BP & HR control is abnormal)?
Also, would they mimick a pheo, ie would they make the adrenal gland show up with Grade 3 uptake on I-123 MIBG scan? Would this mimickry go as far as worsening BP variations with betablockers (I tried both Atenolol & Metoprolol, which resulted in alternative bouts of hypertension & postural hypotension)?
Thanks again for your insights & suggestions.
Hi Dr. Pheo,
ReplyDeleteIt seems one of my siblings has very poor health insurance in both choice and coverage. He has SDHB gene mutation with hypertension. Do you know of any open studies where he and his children could receive treatment? He lives in Pennsylvania.
Thanks for sharing your knowledge.
Dr. Pheo:
ReplyDeleteWith a known SDHB mutation in a young child and a very complex familial history of Pheo's and neuroblostoma, in your professional and medical opinion, what is the chance of developing a pheo?
Thank you,
Kate
I have an unrelated question. Last year I did a 24hr urine test and all the values came out as high normal expect for dopamine. I have multiple HNP. I just received my latest tests back and they show elevated dopamine again but now the epinephrine value was too low to report. I'm at a loss to what this could mean. The doctor is ordering an MIBG scan and 5 HIAA test. I guess I'm confused can you have a pheo and have low epinephrine levels?
ReplyDeleteDear Stacey,
ReplyDeleteHead and neck paras are often non-functioning, meaning they do not produce epinephrine or norepinephrine. So it is totally possible that you have those paras without elevated epinephrine levels.
Dr. Pheo
Dear kate,
ReplyDeleteThe life-time chance of having a pheo or para in a person with SDHB mutation is close to 100%. There is a wide variation on the age when the tumor shows up, even with the same mutation.
Dr. Pheo
Dear Team Burns,
ReplyDeleteI don't know any such trials.
Dr. Pheo
Dear sersem,
ReplyDeleteA small pheo usually does not cause symptoms. Since you do have symptoms, it is unlikely that you have a small pheo that causes all the symptoms. If you have pheo, you should have a sizable one and the markers should be elevated.
It is frustrating to both patients and doctors that a definitive diagnosis can not be reached. Unfortunately it is often not possible initially to make a clear diagnosis in patients with pheo symptoms. My suggestion is that you work closely with a doctor you trust and who is open-minded and interested in you and your disease. With time, a diagnosis is eventually made in most cases.
Dr. Pheo
I understand that (some? all?) embryonic testing involves taking one cell after a small number of divisions (8 or 16 cells) for the genetic testing. Is there any data that removing 1 of say 8 cells either is or is not problematic, perhaps years later in life?
ReplyDeleteDear Jen,
ReplyDeleteIt is a good question. As the pre-implantation diagnosis has been in place for not so long, follow-up is not very long yet. The available evidence suggests that it is safe to remove one of the cells for study.
Dr. Pheo