A 12- year -old boy is referred for evaluation of nocturnal enuresis and sho stature. The blood pressure is normal. The blood urea is 112 mg/dl, creatinine 6 mg/d1, sodium 119 mEq/1, potassium 4 mEq/1, calcium 7mg/d1, phosphate 6mg/dl and alkaline phosphatase 400 U/l.Urinalysis shows trace proteinuria with hyaline casts; no red and white cells are seen. Ultrasound shows bilateral small kidneys and the micturating cystourethrogram is normal. The most likely diagnosis is:

**Core Concept**
The patient is presenting with features of short stature, nocturnal enuresis, and renal dysfunction, necessitating a diagnosis that accounts for these multi-systemic manifestations. The key to this question lies in understanding the pathophysiology of renal disease and its effects on growth and development.

**Why the Correct Answer is Right**
The patient's laboratory findings, including elevated blood urea, creatinine, and alkaline phosphatase, along with the presence of small kidneys on ultrasound, suggest chronic kidney disease (CKD). The presence of nocturnal enuresis and short stature can be attributed to the associated growth hormone resistance and decreased insulin-like growth factor-1 (IGF-1) levels, which are common in CKD. The normal blood pressure and absence of significant proteinuria or hematuria help to rule out other renal disorders such as nephrotic syndrome or glomerulonephritis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is likely a distractor, as it does not correlate with the patient's laboratory findings or ultrasound results. However, it could be a consideration in a patient with a similar presentation and a family history of a genetic disorder.

**Option B:** This option is incorrect because it does not account for the patient's short stature and nocturnal enuresis, which are not typical features of this condition.

**Option C:** This option is incorrect because it does not explain the patient's renal dysfunction or the presence of small kidneys on ultrasound.

**Option D:** This option is incorrect because it does not account for the patient's laboratory findings, including the elevated alkaline phosphatase and small kidneys on ultrasound.

**Clinical Pearl / High-Yield Fact**
In patients with chronic kidney disease, growth hormone resistance and decreased IGF-1 levels can lead to short stature and nocturnal enuresis. This is an important consideration in the evaluation of children with CKD, as it can impact their quality of life and overall prognosis.

**Correct Answer: C. Chronic Kidney Disease**

✓ Correct Answer: C. Chronic glomerulonephritis