Typical blood test values in Thal minor

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Typical blood test values in Thal minor
« on: June 04, 2014, 09:29:43 AM »
Dear All,

Apologies if this has been discussed before. I did an advanced search but I could not find anything.
Last time I went to see my GP he mentioned there are specific normative values for people with BThal minor; however, he couldn't tell me where to find them or who I should contact to find out. I tried to research them on the web, but there seems to be nothing available to the lay public.
Now, I have no idea whether I'm a beta + o beta - (0) minor. I'm due to have new blood tests soon, but one year ago some of the results were as follows: (some values are missing - Gp's printer was not working so he wrote down the 'abnormal values' on a piece of paper - I have omitted two because I can't read them!)

Hb A2  5.8%
HB F <1%
Hb  108
WCC 6.5
MCV 57
MCH 18

Hb and MCV appear 20% lower than they should be if I wasn't a carrier - is that in keeping with beta + o beta -? Or perhaps it is not possible to know  due to a large overlap between the two 'variants' and a genetic test is required?

More generally, is there any way for a lay person to disambiguate between having an allele that produces partially defective haemoglobin  or no haemoglobin at all? Or am I getting confused here about the meaning of beta + and beta - ?

Thanks in advance!


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Offline Andy Battaglia

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Re: Typical blood test values in Thal minor
« Reply #1 on: June 05, 2014, 02:02:38 AM »
See the page at http://www.thalassemiapatientsandfriends.com/index.php/topic,3480.0.html  for blood indexes parameters for thal minor and iron deficiency.

MCV will always be low in beta minor and HbA2 will always be high unless iron deficiency is also present. Majors have an even lower MCV than minors, so there may be a lower MCV with a beta 0, but both will be lower than normal due to the presence of the smaller red blood cells formed found in thalassemia patients minor through major.
Beta 0 minors will usually have a lower Hb than beta + minors, unless there is some modifying factor like coinciding alpha trait. DNA testing can determine the exact type of mutation or deletion. Iron deficiency can also affect values like Hb and MCV and cause them to be even lower.
Andy

All we are saying is give thals a chance.

Re: Typical blood test values in Thal minor
« Reply #2 on: June 05, 2014, 08:42:55 AM »
Thank you very much Andy. For some reason I could not find that page when I searched!

Just one question though - in the second table, it looks like MCV mean value is 85.0 for BTahl major and 77.0 for BThal Minor. Should it not be the opposite? I am probably missing something obvious here.

I am not sure how to go about doing a DNA testing here in the UK. I had a daughter last year and I am waiting to hear back from the haematologist with re: what to do to find out if she inherited the trait. I guess if she did, I will try and find out more about the specific mutation.
Thanks again!

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Offline Andy Battaglia

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Re: Typical blood test values in Thal minor
« Reply #3 on: June 05, 2014, 02:50:23 PM »
The values given for thal major assume the patient is transfusing, so what is measured is the transfused blood in a patient and not what they would be without blood (they would not be alive without blood).

It all depends on whether the health service will cover DNA testing for thal minors. My guess is they won't, as knowing the genotype doesn't make a lot of difference to a minor.
Andy

All we are saying is give thals a chance.

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Offline Andy Battaglia

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Re: Typical blood test values in Thal minor
« Reply #4 on: June 05, 2014, 10:41:03 PM »
This chart shows values for un-transfused major.


Red Blood Cell Index                                 Normal 1      Affected        Carrier 1
                                                          Male   Female        β-Thal Major    β-Thal Minor
Mean corpuscular volume (MCV fl)         89.1±5.01    87.6±5.5      50-70     <79
Mean corpuscular hemoglobin (MCH pg)  30.9±1.9     30.2±2.1      12-20      <27
Hemoglobin (Hb g/dL)                            15.9±1.0    14.0±0.9       <7         Males: 11.5-15.3
                                                                                                       Females: 9.1-14
Andy

All we are saying is give thals a chance.

 

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