Biochemistry
1 questionsAn adult tall male presents with a long arm span, pectus excavatum, and cardiac abnormalities. What is the most likely defective protein?
NEET-PG 2024 - Biochemistry NEET-PG Practice Questions and MCQs
Question 241: An adult tall male presents with a long arm span, pectus excavatum, and cardiac abnormalities. What is the most likely defective protein?
- A. Fibrillin (Correct Answer)
- B. Elastin
- C. Collagen
- D. Myosin
- E. Laminin
Explanation: ***Fibrillin*** - The constellation of **tall stature**, **long arm span**, **pectus excavatum**, and **cardiac abnormalities** (e.g., aortic dissection or mitral valve prolapse) is classic for **Marfan syndrome**. - Marfan syndrome is caused by a defect in the *FBN1* gene, which codes for **fibrillin-1**, a glycoprotein essential for the formation of elastic fibers in connective tissue. *Elastin* - Defects in **elastin** are associated with conditions like **supravalvular aortic stenosis** (due to **Williams syndrome**) or cutis laxa, which have different phenotypic presentations. - While both elastin and fibrillin are components of elastic fibers, the specific features of Marfan syndrome point to fibrillin as the primary defect. *Collagen* - Defects in **collagen** (especially type I, III, or V) are associated with conditions such as **osteogenesis imperfecta** (brittle bones) or **Ehlers-Danlos syndrome** (hypermobility, skin hyperextensibility). - These conditions typically present with different clinical manifestations, lacking the specific combination of features seen in this patient. *Myosin* - **Myosin** is a fibrous protein primarily involved in **muscle contraction** and is not directly implicated in widespread connective tissue disorders affecting skeletal and cardiovascular systems in this manner. - Defects in myosin are more commonly associated with various forms of **cardiomyopathy** or skeletal muscle myopathies, not Marfan-like features. *Laminin* - **Laminin** is a major component of the **basement membrane** and plays a role in cell adhesion, migration, and tissue architecture. - Laminin defects are associated with certain forms of **muscular dystrophy** (e.g., congenital muscular dystrophy) and **epidermolysis bullosa**, not the specific skeletal and cardiovascular features of Marfan syndrome.
Dermatology
1 questionsIdentify the diagnosis based on the dermatology immunofluorescence (IF) image provided.
NEET-PG 2024 - Dermatology NEET-PG Practice Questions and MCQs
Question 241: Identify the diagnosis based on the dermatology immunofluorescence (IF) image provided.
- A. Pemphigus vulgaris
- B. Pemphigus foliaceus
- C. Bullous pemphigoid
- D. Dermatitis herpetiformis (Correct Answer)
Explanation: ***Dermatitis herpetiformis*** - The immunofluorescence image shows **granular IgA deposits** at the **dermal papillae region**, which is characteristic of dermatitis herpetiformis. - This condition is strongly associated with **celiac disease** and presents with intensely pruritic papules and vesicles. *Pemphigus vulgaris* - Immunofluorescence in pemphigus vulgaris typically shows a **fishnet pattern** of IgG deposits throughout the **epidermis**, reflecting antibodies against desmoglein 3 and 1. - This pattern is an intercellular deposition, not granular at the dermal papillae. *Pemphigus foliaceus* - Similar to pemphigus vulgaris, pemphigus foliaceus also exhibits **intercellular IgG deposits** in the epidermis, but it is usually more superficial, targeting desmoglein 1. - The image does not show this intercellular epidermal staining. *Bullous pemphigoid* - Bullous pemphigoid is characterized by **linear IgG and C3 deposits along the dermal-epidermal junction** (basement membrane zone). - The image distinctly shows granular IgA, not linear IgG/C3, and specifically in the dermal papillae.
Internal Medicine
4 questionsWhich of the following statements is correct about Paroxysmal Nocturnal Hemoglobinuria (PNH)?
A patient presents with pulmonary hemorrhage and is P-ANCA positive. What is the most likely diagnosis?
Which of the following is typically observed in the investigation results for a patient with iron deficiency anemia (IDA)?
An adult female presents with pallor and fatigue. Blood investigations show low hemoglobin ( Hb ), low serum iron, low ferritin, low transferrin saturation, and increased total iron-binding capacity (TIBC). What is the likely diagnosis?
NEET-PG 2024 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 241: Which of the following statements is correct about Paroxysmal Nocturnal Hemoglobinuria (PNH)?
- A. Sucrose lysis test is used for the confirmation
- B. Flow cytometry is the best investigation (Correct Answer)
- C. The most common cause of death is heart failure
- D. It is an inherited disorder
Explanation: ***Flow cytometry is the best investigation*** - **Flow cytometry** is the gold standard for diagnosing PNH as it directly detects the absence of **GPI-anchored proteins (CD55 and CD59)** on the surface of red blood cells, granulocytes, and monocytes. - This method is highly sensitive and specific, allowing for the precise quantification of PNH clones even when present in small numbers. *Sucrose lysis test is used for the confirmation* - The **sucrose lysis test** (or sugar-water test) was an older screening test for PNH, but it is **not specific or sensitive enough** for confirmation. - It works by inducing complement activation on PNH cells in low ionic strength sucrose solution [1], but it has a high rate of false positives and negatives. *The most common cause of death is heart failure* - The most common cause of death in patients with PNH is **thrombosis**, particularly in unusual sites such as hepatic, cerebral, or abdominal veins, due to the prothrombotic state caused by the disease. - While heart complications can occur, they are not the leading cause of mortality. *It is an inherited disorder* - PNH is an **acquired clonal disorder** of hematopoietic stem cells, not an inherited genetic disorder [1]. - It results from a somatic mutation in the **PIG-A gene** in a hematopoietic stem cell, leading to the deficiency of GPI-anchored proteins.
Question 242: A patient presents with pulmonary hemorrhage and is P-ANCA positive. What is the most likely diagnosis?
- A. Churg-Strauss syndrome
- B. Microscopic polyangiitis (Correct Answer)
- C. Wegener granulomatosis
- D. Polyarteritis nodosa (PAN)
Explanation: ***Microscopic polyangiitis*** - This condition is characterized by **pulmonary hemorrhage** (often manifesting as diffuse alveolar hemorrhage) and **P-ANCA positivity**, which is typically associated with antibodies against **myeloperoxidase (MPO)**. [1] - It is a **small-vessel vasculitis** that frequently affects the kidneys (glomerulonephritis) and lungs without granuloma formation. *Churg-Strauss syndrome* - While Churg-Strauss syndrome (now known as **Eosinophilic Granulomatosis with Polyangiitis**, EGPA) can be P-ANCA positive, it is typically associated with a history of **asthma**, **allergic rhinitis**, and **eosinophilia**. [1] - Pulmonary involvement often includes **infiltrates** and nodules, but diffuse alveolar hemorrhage with severe pulmonary hemorrhage is less common as the primary presentation compared to MPA. *Wegener granulomatosis* - Wegener granulomatosis (now known as **Granulomatosis with Polyangiitis**, GPA) primarily presents with **upper and lower respiratory tract granulomatous inflammation** and **glomerulonephritis**. - It is typically associated with **C-ANCA positivity** (antibodies against proteinase 3, PR3), not P-ANCA. *Polyarteritis nodosa (PAN)* - Polyarteritis nodosa is a **medium-vessel vasculitis** that typically affects the **kidneys, gastrointestinal tract, skin, and nervous system**. [1] - It is classically **ANCA-negative** and does not typically cause pulmonary hemorrhage or diffuse alveolar hemorrhage.
Question 243: Which of the following is typically observed in the investigation results for a patient with iron deficiency anemia (IDA)?
- A. Increased serum ferritin
- B. Decreased transferrin saturation (Correct Answer)
- C. Increased serum iron
- D. Normal total iron-binding capacity (TIBC)
- E. Increased mean corpuscular volume (MCV)
Explanation: ***Decreased transferrin saturation*** - In **iron deficiency anemia**, there is insufficient iron to bind to **transferrin**, leading to a reduction in the percentage of transferrin that is iron-bound. - This reflects the body's struggle to supply iron for erythropoiesis due to depleted iron stores. *Increased serum ferritin* - **Serum ferritin** is a key indicator of the body's iron stores; in **iron deficiency anemia**, these stores are depleted, leading to a *decreased* rather than increased serum ferritin level. - An increased serum ferritin is typically seen in conditions of **iron overload** or **inflammation**. *Increased serum iron* - **Serum iron** measures the iron circulating in the blood, and in **iron deficiency anemia**, iron levels are *low* due to inadequate intake or excessive loss. - An increased serum iron level would contradict the diagnosis of iron deficiency. *Normal total iron-binding capacity (TIBC)* - **Total iron-binding capacity (TIBC)** typically *increases* in iron deficiency anemia as the liver produces more transferrin in an attempt to capture any available iron. - A normal TIBC would not reflect the compensatory mechanisms seen in iron deficiency. *Increased mean corpuscular volume (MCV)* - **Iron deficiency anemia** is a **microcytic anemia**, characterized by *decreased* MCV due to inadequate hemoglobin synthesis within red blood cells. - An increased MCV is seen in **macrocytic anemias** such as vitamin B12 or folate deficiency, not in iron deficiency.
Question 244: An adult female presents with pallor and fatigue. Blood investigations show low hemoglobin ( Hb ), low serum iron, low ferritin, low transferrin saturation, and increased total iron-binding capacity (TIBC). What is the likely diagnosis?
- A. Iron Deficiency Anemia (IDA) (Correct Answer)
- B. Anemia of Chronic Disease
- C. Hemolytic Anemia
- D. Thalassemia
- E. Sideroblastic Anemia
Explanation: ***Iron Deficiency Anemia (IDA)*** - The unique constellation of **low hemoglobin**, **low serum iron**, **low ferritin**, **low transferrin saturation**, and **increased total iron-binding capacity (TIBC)** is the hallmark of Iron Deficiency Anemia. - **Ferritin** is a direct measure of iron stores, and its low level confirms depletion, while **increased TIBC** signifies the body's attempt to absorb more iron due to deficiency. *Anemia of Chronic Disease* - While also presenting with **low hemoglobin** and often **low serum iron**, Anemia of Chronic Disease is characterized by **normal or increased ferritin** (as ferritin is an acute phase reactant) and **decreased TIBC**. - There is a functional iron deficiency, but iron stores are typically adequate, and inflammation plays a central role. *Hemolytic Anemia* - Hemolytic anemia is characterized by the premature destruction of red blood cells, leading to **low hemoglobin** but typically **normal or elevated serum iron** and ferritin due to iron release from lysed red cells. - Key indicators, such as **elevated bilirubin**, **lactate dehydrogenase (LDH)**, and **reticulocytosis**, are absent in the given scenario. *Thalassemia* - Thalassemia is a genetic disorder causing defective hemoglobin synthesis, resulting in **microcytic hypochromic anemia** with **low hemoglobin**. - However, thalassemia typically presents with **normal to high serum iron** and ferritin levels, as iron absorption may be increased, and there's no primary iron deficiency. *Sideroblastic Anemia* - Sideroblastic anemia is characterized by defective heme synthesis with iron accumulation in mitochondria, forming characteristic ring sideroblasts on bone marrow examination. - Laboratory findings typically show **normal to increased serum iron**, **increased ferritin**, and **increased transferrin saturation**, distinguishing it from iron deficiency anemia.
Pathology
2 questionsAn elderly male patient presented with clinical symptoms and signs consistent with possible multiple myeloma. Electrophoresis shows an M spike, and immunofixation findings are shown below. Which of the following statements best corresponds to the findings?
Which of the following is an intracellular marker or deposition found in Alzheimer's disease?
NEET-PG 2024 - Pathology NEET-PG Practice Questions and MCQs
Question 241: An elderly male patient presented with clinical symptoms and signs consistent with possible multiple myeloma. Electrophoresis shows an M spike, and immunofixation findings are shown below. Which of the following statements best corresponds to the findings?
- A. Multiple myeloma with increased IgM
- B. Multiple myeloma with increased IgG (Correct Answer)
- C. Multiple myeloma with increased IgA
- D. Waldenström macroglobulinemia
Explanation: ***Multiple myeloma with increased IgG*** - The immunofixation image shows a distinct, *monoclonal band (M spike)* in the **IgG lane (G)**, corresponding to the initial electrophoresis (ELP) M spike [1]. There is also a corresponding band in the **kappa light chain (K)** lane [1]. - The presence of a dominant band in IgG, along with a matching light chain (either kappa or lambda), indicates an **IgG monoclonal gammopathy**, which is characteristic of the most common type of multiple myeloma [1]. *Multiple myeloma with increased IgM* - This option would correspond to a strong, monoclonal band in the **IgM lane (M)**, which is not the case here. The 'M' lane in the image shows a faint/normal band, not an increased M spike. - Increased IgM monoclonal protein (M spike) is characteristic of **Waldenström macroglobulinemia**, not typically multiple myeloma [2]. *Multiple myeloma with increased IgA* - If the patient had IgA multiple myeloma, there would be a prominent monoclonal band in the **IgA lane (A)**, which is not observed in this immunofixation result. The 'A' lane shows a considerably smaller band compared to IgG. - IgA multiple myeloma is a less common subtype than IgG myeloma and would present with an IgA M spike [1]. *Waldenström macroglobulinemia* - Waldenström macroglobulinemia is characterized by a monoclonal gammopathy of the **IgM type**, which would present as a distinct M spike in the IgM lane [2]. - The immunofixation clearly shows an **IgG M spike**, ruling out Waldenström macroglobulinemia based on the type of monoclonal gammopathy [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus, pp. 608-609. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus, pp. 606-607.
Question 242: Which of the following is an intracellular marker or deposition found in Alzheimer's disease?
- A. Tau protein (Correct Answer)
- B. A β 40 / 42 (Amyloid-beta 40/42)
- C. Alpha-synuclein
- D. TDP-43
Explanation: ***Tau protein*** - **Tau protein** forms **neurofibrillary tangles** within the neurons, which is a hallmark intracellular lesion in Alzheimer's disease [1]. - These tangles disrupt neuronal transport systems, leading to **synaptic dysfunction** and cell death [1]. *A ̢ 40 / 42 (Amyloid-beta 40/42)* - **Amyloid-beta** peptides aggregate to form **extracellular amyloid plaques**, not intracellular deposits, in Alzheimer's disease [2]. - While central to the pathology, these **plaques** are found outside of the neurons in the brain parenchyma [2]. *Alpha-synuclein* - **Alpha-synuclein** is the primary component of **Lewy bodies**, which are intracellular inclusions characteristic of Parkinson's disease and Lewy body dementia. - It is not a primary marker for Alzheimer's disease pathology. *TDP-43* - **TDP-43 (TAR DNA-binding protein 43)** inclusions are characteristic of **frontotemporal lobar degeneration (FTLD)** and amyotrophic lateral sclerosis (ALS). - While sometimes co-occurs with Alzheimer's, it is not a primary or defining intracellular marker for Alzheimer's disease itself. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1292-1294. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1290-1292.
Pediatrics
1 questionsA child presents with recurrent infections. Mediastinal imaging reveals an absent thymus gland, and further investigations show low ADA (adenosine deaminase) levels. What is the most likely diagnosis?
NEET-PG 2024 - Pediatrics NEET-PG Practice Questions and MCQs
Question 241: A child presents with recurrent infections. Mediastinal imaging reveals an absent thymus gland, and further investigations show low ADA (adenosine deaminase) levels. What is the most likely diagnosis?
- A. Severe Combined Immunodeficiency (SCID) (Correct Answer)
- B. DiGeorge syndrome
- C. X-linked agammaglobulinemia
- D. Hyper-IgM syndrome
- E. Wiskott-Aldrich syndrome
Explanation: ***Severe Combined Immunodeficiency (SCID)*** - **Recurrent infections**, an **absent thymus gland** (indicating severe T-cell deficiency), and **low ADA levels** are classic features of SCID, specifically **ADA deficiency-SCID**. - ADA deficiency leads to the accumulation of toxic metabolites that destroy **B and T lymphocytes**, severely compromising both humoral and cellular immunity. *DiGeorge syndrome* - Characterized by **thymic hypoplasia or aplasia**, leading to T-cell deficiencies and recurrent infections, similar to the absent thymus. - However, DiGeorge syndrome is typically associated with **hypocalcemia** due to parathyroid hypoplasia, and **cardiac defects**, which are not mentioned, and **low ADA levels** are not a feature. *X-linked agammaglobulinemia* - Primarily affects **B-cell development**, leading to a severe deficiency of antibodies, resulting in recurrent bacterial infections. - **T-cell function** and the **thymus gland** are typically normal in this condition, and low ADA levels are not observed. *Hyper-IgM syndrome* - Characterized by normal or elevated levels of **IgM** but very low levels of **IgG, IgA, and IgE** due to defects in B-cell class switching. - The thymus gland is generally normal, and the primary defect lies in antibody production, not T-cell development or ADA deficiency. *Wiskott-Aldrich syndrome* - An X-linked immunodeficiency presenting with recurrent infections, but classically features the triad of **thrombocytopenia with small platelets**, **eczema**, and **immunodeficiency**. - The thymus is typically present, and **low ADA levels** are not characteristic of this syndrome.
Surgery
1 questionsWhich of the following is not seen with ileal resections?
NEET-PG 2024 - Surgery NEET-PG Practice Questions and MCQs
Question 241: Which of the following is not seen with ileal resections?
- A. Microcytic hypochromic anemia
- B. Nuclear cytological asynchrony
- C. Neurological manifestation
- D. Cognitive improvement (Correct Answer)
Explanation: ***Cognitive improvement*** - Ileal resections are associated with malabsorption of various nutrients, but they do not lead to **cognitive improvement**. In fact, nutrient deficiencies (particularly B12) can negatively impact cognitive function. - The effects of ileal resections are primarily related to **digestion** and **absorption**, causing symptoms like diarrhea, weight loss, and specific vitamin deficiencies, not enhanced brain function. - This is the **most obvious answer** to what is "not seen" with ileal resections. *Microcytic hypochromic anemia* - This type of anemia is caused by **iron deficiency**, which is **NOT a direct consequence** of ileal resection. - **Iron absorption** occurs primarily in the **duodenum and proximal jejunum**, not in the ileum. - Ileal resection typically causes **macrocytic anemia** (due to B12 deficiency), not microcytic anemia. - While microcytic anemia could occur indirectly from chronic blood loss in inflammatory bowel disease, it is not a characteristic feature of ileal resection itself. *Nuclear cytological asynchrony* - **Nuclear cytological asynchrony** (megaloblastic changes) is a **direct consequence** of **vitamin B12 deficiency**, which commonly results from terminal ileal resection. - The **terminal ileum** is the primary site for absorption of **vitamin B12** (cobalamin) bound to intrinsic factor. - This manifests as macrocytic anemia with characteristic bone marrow changes. *Neurological manifestation* - **Vitamin B12 deficiency**, resulting from impaired absorption after ileal resection, directly causes various **neurological symptoms**. - These include **peripheral neuropathy**, **subacute combined degeneration of the spinal cord** (posterior and lateral columns), paresthesias, ataxia, memory impairment, and cognitive changes. - Neurological symptoms may occur even before hematological changes become apparent.