Hematology

Question 1

Where do hematologic stem cells originate from?

Answer 1

Mesoderm

Question 2

Timeline of fetal hematopoiesis

Answer 2

Initially-secondary yolk sac
5/6 weeks to 22 weeks gestations : fetal liver
After 22 weeks: bone marrow

Question 3

Fetal hemoglobin is made of

Answer 3

Two alpha chains and two gamma chains

Question 4

Hemoglobin A is made of

Answer 4

Two alpha chains and two beta chains

Question 5

Hemoglobin A2 is made of

Answer 5

Two alpha chains and two delta chains

Question 6

Hemoglobin Barts is made of

Answer 6

Four gamma chains

Question 7

Hemoglobin H is made of

Answer 7

Four beta chains

Question 8

Alpha globin genes: how many and where located

Answer 8

Four genes on chromosome 16

Question 9

Beta globin genes: how many and what chromosome

Answer 9

Two genes on chromosome 11

Question 10

Mutation in sickle cell disease

Answer 10

Valine for glutamic acid at position six (on chromosome 11 in beta globulin gene)

Question 11

Cause of hemoglobin E

Answer 11

Abnormal transcription message in the beta-globulin gene results in decreased production of beta chains; 26 GLU —> LYS

Question 12

How much does 1% fetal hemoglobin represent on a Kleinauer-Betke

Answer 12

50 mL of fetal blood

Question 13

How much RhoGam do you give

Answer 13

Number of vials = mL of fetal blood/15
(1 vial = 300 mcg)

Question 14

How does Apt test work

Answer 14

Add NaOH to sample. Fetal hgb is resistant to alkaline denaturation so will be pink. Adult hemoglobin will be yellow-brown

Question 15

Test for Fanconi Anemia

Answer 15

Test chromosomes with mitomycin C —> increased chromosomal breaks

Question 16

How to calculate Mentzer index?

Answer 16

MCV/#RBC; >13.5 consistent with iron deficiency, <11.5 consistent with thalassemia major

Question 17

Cause of hereditary spherocytosis

Answer 17

Defect in membrane proteins (spectrin, ankyrin, band 3, protein 4.2)

Question 18

Test for hereditary spherocytosis

Answer 18

Osmotic fragility test

Question 19

Inheritance of G6PD deficiency

Answer 19

X-linked recessive

Question 20

What does glucose-6-phosphate dehydrogenase do?

Answer 20

Converts glucose-6-phosphate to Penrose phosphate in the hexose monophosphate shunt pathway (needed to make glucose); requires NADP (which goes to NADPH and is needed to maintain the antioxidants catalase and glutathione)

Question 21

Inheritance of pyruvate kinase deficiency

Answer 21

Autosomal recessive

Question 22

Calculation of blood volume exchanged for partial exchange transfusion

Answer 22

Blood volume exchanged= ((observed hamtocrit-desired hematocrit)/observed hematocrit)* infants blood volume (mL)

Question 23

State of normal iron vs with methemoglobin

Answer 23

Normal is reduced or ferrous state (2+); methemoglobin is oxidized or ferric state (3+)

Question 24

Inheritance pattern of TAR syndrome

Answer 24

Autosomal recessive

Question 25

Inheritance pattern of amegakaryocyte thrombocytopenia

Answer 25

Suspected x-linked transmission; male:female = 2:3

Question 26

Neonatal clotting factors compared to adult levels

Answer 26

Contact (11, 12, prekallekrein, and HMW kininogen) < 70% Vitamin K dependent (2, 7, 9, 10) <70% of adult levels 5, 8, 13, vWF, fibrinogen > 70% ATIII, protein C, protein S: 30% Thrombomodulin: 3x greater

Question 27

Most common hemophilia and its inheritance

Answer 27

Hemophilia A (factor VIII deficiency); c-linked recessive

Question 28

Inheritance pattern of hemophilia B

Answer 28

X-linked recessive (factor IX deficiency)

Question 29

Inheritance pattern of factor XI deficiency

Answer 29

Autosomal recessive (also associated with Noonan syndrome) No degree of correlation between level of deficiency and symptoms unlike hemophilia A and B)

Question 30

Inheritance of factor 13 deficiency

Answer 30

Autosomal recessive; has normal routine clotting studies

Question 31

Calculation for the volume of red blood cells to transfuse in a neonate with acute hemorrhage

Answer 31

Desired increase in hematocrit x 1.6 x weight

Question 32

Normal coagulation profile and infants with vitamin K deficient bleeding

Answer 32

Normal platelet count, increased PT, normal PTT (PTT can become increased with prolonged vitamin K deficiency)

Question 33

Typical blood volume for: Term infant Preterm infant SGA infant

Answer 33

85 mL/kg 100 mL/kg 105 mL/kg

Question 34

Neonate to present with HLH before a month of age frequently having a mutation of the:

Answer 34

Perforin gene in chromosome 10q22.1

Question 35

Areas of the brain, most frequently affected by hyperbilirubinemia

Answer 35

Globus pallidus and subthalamic nucleus

Question 36

MCHC / MCV in spherocytosis

Answer 36

> 0.36

Question 37

What is result if newborn screen shows: FA

Answer 37

Normal, no further action

Question 38

What is result if newborn screen shows: FAS or FAC

Answer 38

Sickle cell carrier or Hemoglobin C carrier, family testing, and counseling

Question 39

What is result if newborn screen shows: FS

Answer 39

Sickle cell anemia, sickle Beta0 thalassemia; start penicillin prophylaxis, refer to hematology, family testing and counseling

Question 40

What is result if newborn screen shows: FSC

Answer 40

Sickle Cell Disease; start penicillin ppx, refer to heme, family testing and counseling

Question 41

What is result if newborn screen shows: FSA

Answer 41

Sickle Beta+ Thalassemia; start penicillin ppx, heme referral, family testing and counseling

Question 42

How is the Kleihauer Bette test done

Answer 42

Blood is treated with citric acid phosphate buffer, fetal cell stay red

Question 43

What can give a false positive result on the Kleihauer-Betke

Answer 43

Anything that increases maternal hemoglobin F such as thalassemia, minor, sickle cell, or hereditary persistence of fetal hemoglobin

Question 44

Anemia, short stature, triphalangeal thumbs

Answer 44

Diamond Blackfan anemia

Question 45

Features of tar syndrome

Answer 45

Thrombocytopenia (from absent megakaryocytes), absent radius but normal thumbs, 30-35% cardiac (TOF or ASD), facial capillary hemangioma, eosinophilia and leukemias reactions

Question 46

Clinical features of amegakaryocytic thrombocytopenia

Answer 46

Severe isolated thrombocytopenia, no other abnormalities, 50% develop aplastic anemia, risk of developing leukemia