A 8-year-old male child presented with complaints of pain and swelling in right distal femur for 5 months and also complained of on and off fever and significant weight loss along with loss of appetite. Lab studies revealed presence of anemia, leucocytosis and raised ESR & LDH. There was no history of any kind of trauma. Below is the X ray of the same patient. Which of the following chromosomal abnormality is characteristic of this lesion?

**Core Concept:**
The question is discussing a pediatric patient presenting with signs and symptoms consistent with a pathological condition. The core concept is the identification of a specific chromosomal abnormality characteristic of the condition described.

In this case, the child exhibits pain, swelling, fever, weight loss, anemia, leucocytosis, elevated ESR and LDH. There is no history of trauma, which suggests a non-traumatic pathology. X-ray findings are also described.

**Why the Correct Answer is Right:**
The correct answer, Turner syndrome (45,X), is a chromosomal abnormality characterized by a partial or complete absence of one of the two X chromosomes. In Turner syndrome, females are born with only one X chromosome (45,X) instead of the normal two (46,XX). This results in a wide range of clinical manifestations, including short stature, gonadal dysfunction, characteristic facial features, and cardiovascular abnormalities.

In this context, Turner syndrome is the correct answer because it is associated with a specific set of clinical features and laboratory findings that align with the described patient's symptoms and laboratory results.

**Why Each Wrong Option is Incorrect:**
A) Klinefelter syndrome (47,XXY) is another chromosomal abnormality but involves an extra Y chromosome in males, causing distinct features unrelated to the presented case.

B) DiGeorge syndrome (22q11.2 deletion) is a chromosomal abnormality associated with congenital heart defects and immunodeficiency, unlike the described patient's symptoms and laboratory findings.

C) Prader-Willi syndrome (45,XO) is characterized by hypotonia, feeding difficulties, and developmental delays, which do not align with the presented patient's symptoms.

D) Down syndrome (trisomy 21) is a chromosomal abnormality associated with mental retardation, distinctive facial features, and congenital heart defects, which are not consistent with the described patient's symptoms and laboratory results.

**Clinical Pearl:**
Turner syndrome is a rare genetic disorder affecting females, characterized by short stature, gonadal dysfunction, characteristic facial features, and cardiovascular abnormalities. Identifying Turner syndrome in a female patient allows for appropriate diagnostic and therapeutic interventions to improve the patient's quality of life, prevent complications, and manage symptoms.

✓ Correct Answer: B. t(11:22)