Model Case Sheet: Chronic Hemolytic Anemia (Hereditary Spherocytosis with Hemolytic Crisis)

Demographic Details & Informant

• Patient Identifier: Master Rohan
• Age / Sex: 5 years / Male
• Date & Time of Examination: 20th September 2026, 10:30 AM
• Father's Name: Mr. Rajesh (Age 35 years, Factory technician, educated up to 10th standard)
• Mother's Name: Mrs. Sunita (Age 32 years, Homemaker, educated up to 12th standard)
• Informant: Mother (reliable, observant, staying continuously with the child)
• Residence: Modinagar, District Ghaziabad, Uttar Pradesh, India
• Socioeconomic Status: Upper-Lower Class (Class IV, Modified Kuppuswamy Scale 2026)
• Reliability of History: Good, consistent chronological narrative

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Chief Complaints

1. Progressive paleness of body and easy fatigability for the past 6 months.
2. Intermittent yellowish discoloration of eyes and passage of dark orange-colored urine for the past 4 months.
3. Dragging heaviness and a progressively enlarging lump in the left upper tummy for the past 1 month.
4. Acute worsening of pallor, dark urine, and mild fever following an upper respiratory illness for the past 4 days.

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History of Present Illness (HOPI)

Master Rohan, a 5-year-old male child, was apparently in his usual state of health until 6 months ago, when his mother first noticed an insidious onset of bodily paleness.

1. Progressive Pallor & Easy Fatigability (Onset, Duration & Progression)

• Initially noticed as mild pallor over the conjunctiva and palmar skin, which progressively deepened over the ensuing 6 months.
• Associated with significant exercise intolerance and easy fatigability over the past 2 months: the child previously played active outdoor games for 1-2 hours without exhaustion, but now stops running within 10-15 minutes, requests to be carried by his mother, and prefers sedentary play.
• No history of bleeding from any site: no epistaxis, gum bleeds, vomiting of blood (hematemesis), passage of black tarry stools (melena), frank rectal bleeding (hematochezia), red spots on skin (petechiae), or spontaneous bruising/hematomas.

2. Scleral Icterus & Urine Color (Hemolytic vs Obstructive Pattern)

• Four months prior to presentation, the mother noticed fluctuating, yellowish discoloration of the whites of both eyes (scleral icterus).
• The jaundice fluctuated in intensity—deepening noticeably during intercurrent febrile illnesses and partially fading during periods of good health, but never clearing completely.
• Associated with passage of dark orange-yellow colored urine. The mother specifically notes that the urine does not deeply stain clothing brown or yellow (acholuric jaundice).
• No history of clay-colored or chalky white stools (acholic stools).
• No history of pruritus, generalized body itching, night scratching, or excoriations (ruling out cholestatic pruritus).

3. Abdominal Distension & Splenic Mass

• One month ago, the mother noticed a firm, non-tender fullness in the left upper quadrant of the abdomen while bathing the child.
• Associated with dragging discomfort in the left hypochondrium and early satiety: the child complains of feeling "full" after eating half of his usual meal volume.
• No history of visible superficial veins across the abdomen, eversion of umbilicus, or pedal edema.
• No history of severe colicky right upper quadrant abdominal pain, bilious vomiting, or intolerance to fatty foods (screening for acute cholecystitis/cholelithiasis).

4. Acute Hemolytic Exacerbation (Past 4 Days)

• Four days prior to admission, the child developed a low-grade fever with clear rhinorrhea and dry cough.
• Over the next 48 hours, the mother observed an acute, dramatic deepening of facial and palmar pallor, accompanied by listlessness, dark amber/tea-colored urine, and rapid breathing while playing, prompting emergency hospital evaluation.
• No history of sudden extreme prostration without jaundice or severe bone pain (screening for aplastic crisis).
• No history of ingestion of fava beans, mothballs (naphthalene), oxidant drugs (co-trimoxazole, dapsone, primaquine), or native unlabelled powders (ruling out acute G6PD oxidative hemolysis).

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Negative History (3C 1D Framework)

Category	Pertinent Negative Elicited	Diagnostic Rationale & Clinical Significance
Causes	Dietary / Blood Loss: No history of prolonged exclusive breastfeeding, excessive cow's milk intake ($>500\text{ mL/day}$), worm infestation (pica/geophagia), or chronic diarrhea. Drugs / Oxidants: No intake of sulfonamides, antimalarials, native herbal preparations, or exposure to mothballs. Transfusions: No history of prior blood transfusions in the child.	Rules out nutritional iron deficiency anemia. Rules out acquired drug-induced oxidative hemolysis or G6PD crisis. Confirms transfusion-naive baseline state.
Complaints (Differentiating)	Thalassemia Major: No history of transfusion dependency starting in infancy ($<6-9\text{ months}$); no frontal bossing or maxillary hyperplasia. Autoimmune Hemolytic Anemia (AIHA): No history of systemic lupus features (malar rash, joint pains, oral ulcers, alopecia). Leukemia / Infiltrative: No high unremitting fever, severe bone tenderness, limb limping, or purpura.	Thalassemia major typically presents in early infancy; HS often presents in childhood with mild-to-moderate anemia. AIHA is usually acute without positive multigenerational family pedigree. Excludes acute lymphoblastic leukemia (ALL).
Complications	Aplastic Crisis: No history of acute plummeting pallor with complete absence of reticulocytes or transient disappearance of jaundice. Congestive Cardiac Failure (CCF): No history of orthopnea, nocturnal cough, puffiness of face, or dependent pedal edema. Biliary Colic: No acute agonizing right hypochondriac colicky pain radiating to right shoulder.	Parvovirus B19 aplastic crisis is a life-threatening emergency in chronic hemolytic anemias. Assesses hemodynamic stability and cardiac compensation. Screens for symptomatic pigmented cholelithiasis.
Differentials	Congestive Splenomegaly (EHPVO): No history of neonatal umbilical vein catheterization, omphalitis, or recurrent massive hematemesis. Gaucher Disease: No history of agonizing bone crises, pathological fractures, or developmental regression.	Differentiates isolated portal hypertension from primary hemolytic anemia. Rules out lysosomal storage disorders.

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Past & Medical History

• Past Illnesses: No history of neonatal exchange transfusion; however, mother recalls the child had neonatal jaundice requiring 48 hours of phototherapy in the maternity hospital before discharge on Day 4 of life.
• Previous Hospitalizations: No prior hospital admissions; no blood transfusions received till date.
• Drug & Allergy History: No known drug allergies; no regular long-term medications.

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Birth, Perinatal & Developmental History

• Antenatal Period: Full-term pregnancy, booked and supervised at a community health center. Mother received iron-folic acid tablets and two doses of tetanus toxoid. No maternal fever with rash or history of gestational diabetes / hypertension.
• Natal History: Normal spontaneous vaginal delivery at a civil hospital; cried immediately at birth. Birth weight: $2.9\text{ kg}$ (normal).
• Postnatal History: Developed visible jaundice on Day 2 of life; managed with phototherapy for 2 days. Discharged on exclusive breastfeeding on Day 5.
• Developmental Milestones: Attained gross motor, fine motor, language, and social milestones appropriately for age. Currently speaks in full sentences, climbs stairs independently, and attends nursery school.

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Immunization History

• Fully immunized for age as per the National Immunization Schedule (NIS): received BCG, OPV-0, Hepatitis B-0 at birth; Pentavalent (DPT+HepB+Hib), IPV, Rotavirus, and PCV at 6, 10, 14 weeks; MR 1st dose and JE 1st dose at 9 months; DPT booster, MR 2nd dose at 16-24 months.
• Special Vaccines: Has not yet received Pneumococcal polysaccharide booster (PPSV23) or Meningococcal conjugate vaccines (will be indicated prior to elective splenectomy).

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Dietary History & Nutritional Calculations

24-Hour Dietary Recall Table

The child is on a mixed household diet. 24-hour recall of actual intake:

Meal Time	Food Item & Quantitative Description	Household Measure	Calories ($ ext{kcal}$)	Proteins ($ ext{g}$)
7:30 AM	Boiled cow's milk with 1 teaspoon sugar	1 small cup ($150\text{ mL}$)	130	4.5
9:00 AM	Wheat chapati with small drop of ghee + dal	1 medium chapati + $1/2$ katori dal	145	4.5
1:00 PM	Boiled white rice with thin moong dal + potato sabzi	1 katori rice + 1 katori dal	220	5.5
5:00 PM	Milk with 2 Marie biscuits	1 small cup ($100\text{ mL}$) + 2 biscuits	110	3.5
8:30 PM	Wheat chapati + cooked bottle gourd (lauki)	1 chapati + $1/2$ katori vegetable	115	2.5
Total Intake			720 kcal	20.5 g

Quantitative Dietary Analysis

$$\text{Ideal Body Weight (IBW for age, 50th centile WHO)} = 18.0\text{ kg}$$

The expected calories and proteins should be calculated from the ideal body weight, not from current weight.

• Calorie Requirement for Age (WHO/ICMR $\approx 85-90\text{ kcal/kg/day}$ based on IBW $18.0\text{ kg}$): $$\text{Target Daily Calorie Intake} = 18.0 \times 85 = 1530\text{ kcal/day}$$ $$\text{Calorie Deficit} = 1530 - 720 = 810\text{ kcal/day } (52.9\%\text{ deficit})$$
• Protein Requirement for Age (WHO/ICMR $pprox 1.1\text{ g/kg/day}$ based on IBW $18.0\text{ kg}$): $$\text{Target Daily Protein Intake} = 18.0 \times 1.1 = 19.8\text{ g/day}$$ $$\text{Actual Protein Intake} = 20.5\text{ g/day } (\text{Adequate protein quantity; calorie-dense supplementation needed})$$

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Family History & Three-Generation Genogram

Family Narrative

• Non-consanguineous marriage.
• Mother (Mrs. Sunita, 32y): Suffered from recurrent jaundice and mild anemia during childhood; underwent elective open splenectomy and cholecystectomy at 14 years of age with complete resolution of symptoms. Peripheral smear shows persistent spherocytes.
• Maternal Grandfather (Mr. Ramcharan): Underwent cholecystectomy at age 28 years for pigmented gallstones; died of unrelated myocardial infarction at age 68.
• Maternal Aunt (Age 29y): Has mild chronic pallor and scleral icterus; diagnosed with spherocytosis.
• Father (Mr. Rajesh, 35y): Healthy, no history of anemia or jaundice.
• Younger Sister (Age 2y): Screened following proband's admission; found to have mild asymptomatic spherocytosis on smear (Hb $10.5\text{ g/dL}$, reticulocytes $4.2\%$).
• Inheritance Pattern: Classical Autosomal Dominant transmission with variable clinical penetrance across three successive generations.

Genogram Embed

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Physical Examination

1. General & Behavioral Assessment

• Child State: Conscious, alert, slightly listless, resting comfortably in mother's lap, cooperative during examination. No irritability or apathy.
• Facies: Normal facial architecture. Absence of thalassemic / hemolytic facies (no prominent frontal bossing, malar prominence, or depressed nasal bridge).

2. Vital Signs & Anthropometry

• Heart Rate: $118\text{ beats/min}$, regular, good volume, synchronous, no radio-femoral delay (hemodynamic tachycardia secondary to anemia).
• Respiratory Rate: $24\text{ breaths/min}$, normal vesicular pattern, no subcostal/intercostal indrawing.
• Blood Pressure: $96/60\text{ mmHg}$ (right upper limb, supine, appropriate pediatric cuff).
• Capillary Refill Time (CRT): $<2\text{ seconds}$ over the sternum.
• SpO2: $98\%$ on room air.
• Temperature: $98.8^\circ\text{F}$ (afebrile at time of exam).
• Anthropometric Parameters:
  • Weight: $16.2\text{ kg}$ ($Z$-score: $-0.85\text{ SD}$, normal range).
  • Height: $108.5\text{ cm}$ ($Z$-score: $-0.45\text{ SD}$, normal range).
  • Weight-for-Height: $Z$-score $-0.6\text{ SD}$ (no wasting).
  • Mid-Upper Arm Circumference (MUAC): $14.6\text{ cm}$ (adequate).
  • Head Circumference: $50.2\text{ cm}$ (normal).

3. Head-to-Toe Stigmata of Chronic Hemolytic Anemia

• Pallor: Severe, prominent over lower palpebral conjunctiva, dorsum of tongue, soft palate, nail beds, and palmar creases.
• Icterus: Moderate scleral icterus present in both eyes; sublingual mucosa faintly icteric.
• Cyanosis / Clubbing: Absent; no digital clubbing (Lovibond angle preserved).
• Lymphadenopathy: No palpable cervical, axillary, or inguinal lymphadenopathy.
• Edema: Absent; no pedal or presacral pitting edema.
• Skin & Nails: Skin is pale and warm; nails show normal curvature (no koilonychia or spooning); no petechiae, ecchymoses, or leg ulcers over medial malleoli.

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Systemic Examination

1. Abdomen Examination

• Inspection: Symmetrically distended in the left upper quadrant; umbilicus centrally placed, inverted; no visible superficial engorged collaterals; all quadrants move equally with respiration; no hernial site impulses.
• Palpation:
  • Spleen: Palpable $4.0\text{ cm}$ below the left costal margin along the long axis towards the right iliac fossa; firm in consistency, smooth surface, non-tender, sharp anterior border with a distinct splenic notch felt on deep inspiration. Does not cross the midline.
  • Liver: Palpable $2.0\text{ cm}$ below the right costal margin in the mid-clavicular line; soft, smooth surface, non-tender, sharp margin. Total liver span is $8.5\text{ cm}$ (normal for 5 years: $8.0-9.0\text{ cm}$).
  • Kidneys: Neither kidney is ballottable.
  • Tenderness: No tenderness over the right hypochondrium (Murphy's sign negative).
• Percussion: Tympanitic note over the rest of the abdomen; splenic dullness confirmed in the left hypochondrium; no shifting dullness or fluid thrill (ascites absent).
• Auscultation: Normal active bowel sounds ($4-5\text{ sounds/min}$); no arterial bruits over renal or epigastric vessels; no splenic friction rub.

2. Cardiovascular System (CVS)

• Inspection & Palpation: Apex beat localized to the 4th intercostal space, $1\text{ cm}$ medial to the mid-clavicular line; normal tapping impulse; no parasternal heave or thrill.
• Auscultation:
  • Normal first and second heart sounds ($S_1, S_2$).
  • Functional Hemic Systolic Murmur: Grade II/VI soft, blowing, early systolic flow murmur heard best at the pulmonary area and left upper sternal border, not radiating, intensifies in high-output states and diminishes on resting.

3. Respiratory System

• Normal vesicular breath sounds bilaterally; no wheezing, rhonchi, or crepitations. Symmetrical chest expansion ($2.5\text{ cm}$).

4. Central Nervous System (CNS)

• Conscious, oriented, speech fluent; cranial nerves I to XII intact; normal muscle bulk and tone; power $5/5$ in all four limbs; deep tendon reflexes $2+$ symmetrical; plantars flexor bilaterally.

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Diagnostic Synthesis & Algorithmic Pathway

flowchart TD
    A["Child with Pallor, Scleral Icterus & Splenomegaly<br>(Master Rohan, 5y / M)"] --> B["Reticulocyte Count & Peripheral Blood Smear"]
    B --> C["High Reticulocyte Count (11.5%)<br>Microspherocytes (>25%)"]
    C --> D["Direct Antiglobulin Test (DAT / Coombs)"]
    D -->|"DAT Positive"| E["Autoimmune Hemolytic Anemia (AIHA)"]
    D -->|"DAT Negative"| F["Congenital Red Cell Membranopathy<br>(Hereditary Spherocytosis)"]
    F --> G["Confirmatory Testing"]
    G --> H["Flow Cytometric EMA Binding Test<br>(MFI reduced >21%)"]
    G --> I["Incubated Osmotic Fragility Test<br>(Increased lysis in hypotonic saline)"]
    H --> J["Definitive Diagnosis: Hereditary Spherocytosis<br>Autosomal Dominant (Mother & Grandfather affected)"]
    J --> K["Abdominal USG: Check Spleen Size & Pigmented Gallstones"]

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Laboratory & Imaging Investigations

1. Complete Hemogram & Reticulocyte Panel

Investigation Parameter	Patient Result	Biological Reference Range	Clinical Interpretation
Hemoglobin (Hb)	6.2 g/dL	$11.5 - 13.5\text{ g/dL}$	Moderate-to-severe normocytic hyperchromic anemia
RBC Count	2.2 × 10¹²/L	$4.0 - 5.2 \times 10^{12}/\text{L}$	Decreased due to active extravascular hemolysis
Packed Cell Volume (PCV / Hematocrit)	18.5%	$34.0 - 40.0\%$	Markedly decreased
Mean Corpuscular Volume (MCV)	76.0 fL	$75.0 - 87.0\text{ fL}$	Normal (spherocytes small, reticulocytes large $\rightarrow$ normal mean)
Mean Corpuscular Hemoglobin (MCH)	28.2 pg	$25.0 - 31.0\text{ pg}$	Normal range
MCHC	36.8 g/dL	32.0 - 36.0 g/dL	Elevated (>36 g/dL): Hallmark of spherocyte membrane condensation
Red Cell Distribution Width (RDW)	18.4%	$11.5 - 14.5\%$	Elevated (anisopoikilocytosis: spherocytes vs reticulocytes)
Total Leukocyte Count (TLC)	8,400 /mm³	$5,000 - 12,000/\text{mm}^3$	Normal (no leukocytosis/leukemia)
Platelet Count	2.6 × 10⁵ /mm³	$1.5 - 4.5 \times 10^5/\text{mm}^3$	Normal (isolated red cell lineage involvement)
Reticulocyte Count (Supravital Stain)	11.5%	0.5 - 2.0%	Marked reticulocytosis: Hyperactive marrow erythropoiesis
Corrected Reticulocyte Count (CRC)	5.2%	$>2-3\%$ in hemolysis	$\text{Retic} \times \frac{\text{Actual Hct}}{\text{Normal Hct}} = 11.5 \times \frac{18.5}{40} = 5.3\%$
Reticulocyte Production Index (RPI)	2.6	$>2.0$	Hyper-regenerative hemolytic marrow response

2. Peripheral Blood Film (PBF) Examination

• RBC Morphology: Marked anisocytosis. Classical presence of numerous microspherocytes ($>25\%$ of all red cells)—small, rounded, intensely hyperchromic cells completely devoid of central pallor. Significant polychromasia representing circulating reticulocytes. Occasional nucleated RBCs ($2/100\text{ WBC}$).
• Absent Morphologies: No target cells (rules out thalassemia), no sickle or drepanocytic cells, no schistocytes or helmet cells (rules out microangiopathic hemolysis / HUS), no basophilic stippling (rules out lead poisoning).
• WBC & Platelets: Normal morphology and adequate numbers; no blast cells or toxic granules.

3. Hemolysis Biomarkers & Direct Antiglobulin Test

Test Parameter	Result	Normal Range	Significance
Serum Total Bilirubin	4.8 mg/dL	$0.2 - 1.2\text{ mg/dL}$	Significant hyperbilirubinemia
Serum Direct (Conjugated) Bilirubin	0.6 mg/dL	$0.0 - 0.3\text{ mg/dL}$	Normal
Serum Indirect (Unconjugated) Bilirubin	4.2 mg/dL	0.2 - 0.8 mg/dL	Unconjugated Hyperbilirubinemia (87.5% of total)
Serum Lactate Dehydrogenase (LDH)	780 U/L	$120 - 300\text{ U/L}$	Elevated: Extravascular & intramarrow red cell destruction
Serum Haptoglobin	<10 mg/dL	$30 - 200\text{ mg/dL}$	Profoundly depleted (cleared by splenic reticuloendothelial system)
Direct Antiglobulin Test (DAT / Coombs)	NEGATIVE	Negative	Rules out Autoimmune Hemolytic Anemia (AIHA)
Urine Routine & Microscopy	Amber color, $pH 6.0$, Albumin nil, Sugar nil, RBC nil	Normal	Dark color due to high urobilinogen; no hemoglobinuria
Urine Bilirubin	Negative	Negative	Acholuric jaundice (unconjugated bilirubin is albumin-bound)
Urine Urobilinogen	Strongly Positive (++++)	Trace / Normal	High intestinal stercobilinogen reabsorbed and excreted in urine

4. Specialized Confirmatory Tests for Hereditary Spherocytosis

• Flow Cytometric Eosin-5-Maleimide (EMA) Binding Test:
  • Result: Mean Fluorescence Intensity (MFI) of patient RBCs is reduced by 28% compared to concurrent age-matched control red cells.
  • Interpretation: Diagnostic of significant deficiency of Band 3 / Rh-related proteins, confirming Hereditary Spherocytosis (Sensitivity $>93\%$, Specificity $>98\%$).
• Incubated Osmotic Fragility Test (at 37°C for 24 hours):
  • Result: Increased osmotic fragility: hemolysis begins at $0.65\%\text{ NaCl}$ (normal control: begins at $0.45-0.50\%\text{ NaCl}$) and is complete at $0.40\%\text{ NaCl}$. Shift of the fragility curve to the right.
• High-Performance Liquid Chromatography (HPLC / Hb Electrophoresis):
  • $\text{HbA} = 96.2\%$, $\text{HbA}_2 = 2.4\%$ (normal $<3.5\%$), $\text{HbF} = 0.8\%$ (normal $<1.0\%$). Rules out Beta-Thalassemia Major/Intermedia and Sickle Cell Disease.

5. Ultrasonography of Abdomen

• Spleen: Markedly enlarged, measuring $11.8\text{ cm}$ in bipolar axis (normal for 5 years: $\le 8.5\text{ cm}$); homogeneous parenchyma without focal abscess or infarction.
• Liver: Normal size ($8.6\text{ cm}$ span), normal echotexture; intrahepatic biliary radicals not dilated.
• Gallbladder: Shows normal wall thickness, but lumen reveals multiple small acoustic shadowing calculi (pigmented calcium bilirubinate cholelithiasis), largest measuring $4.2\text{ mm}$, without acoustic evidence of acute cholecystitis or biliary sludge.

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Final Clinical Diagnosis Formulation

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Comprehensive 4-Phase Management Plan

Phase 1: Acute Stabilization & Transfusion Protocol

1. Admission & Monitoring: PICU/high-dependency bed; monitor pulse, respiratory rate, SpO2, and strict fluid balance.
2. Packed Red Blood Cell (PRBC) Transfusion:
   • Indication: Symptomatic severe anemia with $\text{Hb } 6.2\text{ g/dL}$, tachycardia ($118/\text{min}$), and functional flow murmur.
   • Transfusion Volume Calculation: $$\text{PRBC Volume (mL)} = \text{Weight (kg)} \times (\text{Target Hb} - \text{Actual Hb}) \times 4$$ $$\text{Target Hb} = 10.0\text{ g/dL} \implies 16.2 \times (10.0 - 6.2) \times 4 = 16.2 \times 3.8 \times 4 \approx 246\text{ mL}$$
   • Administration: Administer $10\text{ mL/kg}$ ($160\text{ mL}$) of leucodepleted packed red cells slowly over 4 hours.
   • Pre-medication: IV Furosemide ($0.5-1.0\text{ mg/kg} = 15\text{ mg}$) at the mid-point of transfusion to prevent volume overload.

Phase 2: Chronic Maintenance & Prophylaxis

1. Folic Acid Supplementation:
   • Oral Folic Acid $2.5\text{ mg/day}$ continuously to support hyperactive marrow erythropoiesis and prevent acute megaloblastic crisis.
2. Avoidance of Iron Therapy:
   • VIVA TRAP: Iron therapy is strictly contraindicated unless concurrent iron deficiency is proven by ferritin $<12\text{ mcg/L}$. Chronic hemolysis causes tissue iron accumulation; unnecessary iron risks secondary hemosiderosis!
3. Fever Emergency Protocol:
   • Educate parents that any acute fever $>38.5^\circ\text{C}$ requires prompt medical evaluation and complete hemogram within 12 hours to rule out Parvovirus B19 aplastic crisis or pneumococcal sepsis.

Phase 3: Elective Surgical Protocol (Splenectomy & Cholecystectomy)

1. Surgical Candidacy:
   • Indicated due to moderate-to-severe disease with hemolytic crises, persistent moderate splenomegaly, and documented pigmented cholelithiasis.
2. Optimal Age & Timing:
   • Deferred until $\ge 6$ years of age (currently 5 years; maintain on folic acid and defer elective surgery by 12 months) to allow maturation of splenic immune competence and prevent Overwhelming Post-Splenectomy Infection (OPSI).
3. Pre-Splenectomy Immunization Protocol (Mandatory $\ge 2-4$ weeks prior):
   • 13-valent Pneumococcal Conjugate Vaccine (PCV13) followed by 23-valent Polysaccharide Vaccine (PPSV23) 8 weeks later.
   • Quadrivalent Meningococcal Conjugate Vaccine (MenACWY) and Meningococcal B Vaccine.
   • Haemophilus influenzae type b (Hib) Booster.
   • Annual Inactivated Influenza Vaccine.
4. Surgical Procedure:
   • Elective Laparoscopic Total (or Subtotal/Partial) Splenectomy combined with Laparoscopic Cholecystectomy.
5. Post-Splenectomy Antibiotic Prophylaxis:
   • Oral Penicillin V ($250\text{ mg}$ orally twice daily) or Amoxicillin ($20\text{ mg/kg/day}$), maintained until at least 18 years of age (or lifelong).

Phase 4: Family Screening & Genetic Counseling

1. Screening of Siblings: Younger sister (2y) already screened; maintain on folic acid; follow up annually with abdominal USG.
2. Genetic Counseling: Explain $50\%$ recurrence risk for future pregnancies in autosomal dominant transmission.