Skip to main content

Describe the relationship among the various hemoglobin's in first year of life and their implication in diagnosing hereditary hemoglobinopathies.

Hemoglobin is tetramer of 4 globin chain + heme( Fe containing porphyrin ring).

Hb F has 2 alpha chains and 2 beta chains which is replaced by Hb A which has 2 aplha chains and 2 beta chains.

Hemoglobin F   -   α2 γ2

Hemoglobin A   -  α2 β2

Normal replacement goes as below

  • By 6-8wk HbF is predominate hb
  • By 24wk 
    • HbF constitute 90% of Hb
    • HbA constitute 5-10% of Hb
  • By 6-12mo postnatal age
    • HbF is <2% of total Hb
    • HbA reaches adult level
There could be deviations in this replacement due to mutations in gene which cause replacement of amino acids and forms defective hemoglobins.
Diagnosis is done by HPLC (High Performance Liquid Chromatography) or IEF (Thin layer/Isoelectric Focusing). 

F - fetal Hb
S - sickle Hb
SS - Homozygous SCD
AS - Sickle cell trait
Sβ - Sickle thalassemia
C -  Hb C
SC - sickle-hemoglobin C
A stands for adult Hb
HPFH - Hereditary Presence of Fetal Hemoglobin

Hb are written from greater to lower quantity.

Report

Possibilities

FS

  • SCD SS

  • SCD Sβ thal

  • S HPFH

FSC

  • SCD SC

FSA

  • SCD Sβ thal (Hb S>50%, HbA2>3.5%)

FAS

  • SCD AS (rule out blood transfusion)

AFS

Transfusion is received so can be

  • SCD SS

  • SCD Sβ thal

FS Other

  • SCD Sβ thal

  • SCD SD, SO, SC, S


F98%A22%

β thalassemia major

A65-88%F10-30%,A22-5%

β thalassemia intermediate

↑ A2, variable F

β thalassemia trait

A2 absent

𝛿 thalassemia

Bart: 1-2%

α thalassemia 1 gene deletion

Bart: 5-10%

α thalassemia 2 genes deletion

Bart: 20-30%

α thalassemia 3 genes deletion

Bart: 90% c Grower 1,2 & Portland

α thalassemia 4 genes deletion

Comments

Post a Comment

Popular posts from this blog

IAP Guidelines on junk food and fruit juices

 Target group: 1. Infants and adolescents aged between 6mo - 18yrs. 2. Children with normal growth and nutrition. 3. Not applicable to malnourished or ill children 4. Do not pertain to commercial formulations and therapeutic diets. THE JUNCS FOODS: J - JUNK Food: "foods (packed or non-packed, processed or non-processed) which contains little or limited presence of proteins, vitamins, phytochemicals, minerals and dietary fiber but are rich in fat (saturated fatty acids), salt and sugar and high in energy (calories) that are known to have negative impact on health if consumed regularly or in high amounts." U - Ultra Processed Foods "formulations of ingredients, mostly of exclusive industrial use that result from a series of industrial processes, including fractioning of whole foods into substances (sugars, oils and fats, proteins, starches and fiber), hydrolysis or hydrogenation, food assembly, coloring and flavouring." N - Nutritionally inappropriate foods C- Caffe...
Post a Comment
Read more

Psychosocial screening in adolescents

Screen used in psychosocial screening of adolescent: HEADSS H: Home: ● Who lives with the young person? Where? ● Do they have their own room? ● What are relationships like at home? ● What do parents and relatives do for a living? ● Ever institutionalized? Incarcerated? ● Recent moves? Running away? ● New people in home environment? E: Education & Employment: ● School/grade performance--any recent changes? Any dramatic past changes? ● Favorite subjects--worst subjects? (include grades) ● Any years repeated/classes failed ● Suspension, termination, dropping out? ● Future education/employment plans? ● Any current or past employment? ● Relations with teachers, employers--school, work attendance? A: Activities: ● On own, with peers (what do you do for fun?, where? when?) ● With family? ● Sports--regular exercise? ● Church attendance, clubs, projects? ● Hobbies--other activities? ● Reading for fun--what? ● TV--how much weekly--favorite shows? ● Favorite music? ● Does y...
Post a Comment
Read more