Int J Clin Pediatr

International Journal of Clinical Pediatrics, ISSN 1927-1255 print, 1927-1263 online, Open Access

Article copyright, the authors; Journal compilation copyright, Int J Clin Pediatr and Elmer Press Inc

Journal website https://ijcp.elmerpub.com

Case Report

Volume 15, Number 1, March 2026, pages 31-36

Urine Spot Beta2-Microglobulin as a Screening Tool for Dent Disease Type 1

↓ Figure 1. Flow diagram for evaluation of Dent disease (adapted from Reference [5]). CKD: chronic kidney disease; FS: Fanconi syndrome; LMWP: low-molecular-weight proteinuria.

↓ **Table 1.** Laboratory Investigations
Test	Case 1	Case 2	Normal range
ANA: anti-nuclear antibody; ANCA: anti-neutrophil cytoplasmic antibody; Cl: chloride; GBM: glomerular basement membrane; HBSAg: hepatitis B surface antigen; HCO₃: bicarbonate; HCV: hepatitis C virus; HPF: high-power field; HIV: human immunodeficiency virus; K: potassium; Na: sodium; PCR: protein-to-creatinine ratio; RBC: red blood cell; WBC: white blood cell.
Blood investigations
Blood urea (mg/dL)	18	20	10–40
Serum creatinine (mg/dL)	0.3	0.4	0.3–0.7
Serum electrolyte (Na, K, Cl, HCO₃) (mEq/L)	137/4.0/100/23	138/4.2/99/22	135–145, 3.5–5.0, 98–107, 20–28
Serum albumin (g/dL)	3.8	3.8	3.5–5.0
Serum cholesterol (mg/dL)	120	156	< 170
Serum calcium (mg/dL)	9.5	10	8.8–10.8
Serum phosphorus (mg/dL)	4.8	4.2	4.0–6.0
Alkaline phosphatase (U/L)	322	298	150–380
Venous blood gas analysis	pH 7.40	pH 7.39	7.32–7.42
Urine analysis
Albumin dipstick	2+	2+	Nil
Glucose	Nil	Nil	Nil
pH	5	5.5	5–8
WBC	0–2/HPF	0–1/HPF	0–5/HPF
RBC	0–2/HPF	0–2/HPF	0–5/HPF
Urine PCR (mg/mg)	3.2	2.8	< 0.2
24-h urine protein (mg/m²/h)	42 (605 mg)	49 (820 mg)	< 4
Urine calcium creatinine ratio (mg/mg)	0.65	0.56	< 0.2
24-h urine calcium (mg/kg/day)	5	5.9	< 4
Urine spot beta2 microglobulin (ng/mL)	> 20,000	> 20,000	< 300
Immunology/infection workup
Viral serology-HIV, HBSAg, HCV	Negative	Negative
Complement C3/C4 (mg/dL)	98/20	102/24
ANA/ANCA/anti-GBM	Negative	Negative
Renal ultrasound	Normal	Normal initially Medullary nephrocalcinosis at follow-up

↓ Table 1. Laboratory Investigations

Test

Case 1

Case 2

Normal range

ANA: anti-nuclear antibody; ANCA: anti-neutrophil cytoplasmic antibody; Cl: chloride; GBM: glomerular basement membrane; HBSAg: hepatitis B surface antigen; HCO₃: bicarbonate; HCV: hepatitis C virus; HPF: high-power field; HIV: human immunodeficiency virus; K: potassium; Na: sodium; PCR: protein-to-creatinine ratio; RBC: red blood cell; WBC: white blood cell.

Blood investigations

Blood urea (mg/dL)

10–40

Serum creatinine (mg/dL)

0.3

0.4

0.3–0.7

Serum electrolyte (Na, K, Cl, HCO₃) (mEq/L)

137/4.0/100/23

138/4.2/99/22

135–145, 3.5–5.0, 98–107, 20–28

Serum albumin (g/dL)

3.8

3.5–5.0

Serum cholesterol (mg/dL)

120

156

< 170

Serum calcium (mg/dL)

9.5

8.8–10.8

Serum phosphorus (mg/dL)

4.8

4.2

4.0–6.0

Alkaline phosphatase (U/L)

322

298

150–380

Venous blood gas analysis

pH 7.40

pH 7.39

7.32–7.42

Urine analysis

Albumin dipstick

Nil

Glucose

Nil

5.5

5–8

WBC

0–2/HPF

0–1/HPF

0–5/HPF

RBC

0–2/HPF

0–5/HPF

Urine PCR (mg/mg)

3.2

2.8

< 0.2

24-h urine protein (mg/m²/h)

42 (605 mg)

49 (820 mg)

< 4

Urine calcium creatinine ratio (mg/mg)

0.65

0.56

< 0.2

24-h urine calcium (mg/kg/day)

5.9

< 4

Urine spot beta2 microglobulin (ng/mL)

> 20,000

< 300

Immunology/infection workup

Viral serology-HIV, HBSAg, HCV

Negative

Complement C3/C4 (mg/dL)

98/20

102/24

ANA/ANCA/anti-GBM

Negative

Renal ultrasound

Normal

Normal initially
Medullary nephrocalcinosis at follow-up

↓ **Table 2.** Urine Beta2 Microglobulin and Genetic Analysis of Cases and Family Members
	Case 1	Case 1 mother	Case 2	Case 2 mother	Case 2 maternal grandfather
ACMG: American College of Medical Genetics; bp: base pair; CES: clinical exome sequencing; SS: Sanger sequencing; NA: not applicable; VUS: variant of uncertain significance.
Urine spot beta2 microglobulin (normal < 300 ng/mL)	> 20,000	110	> 20,000	1,460	106 (post renal transplant)
Genetic study	CES	SS	CES	SS	CES
Gene	CLCN5	CLCN5	CLCN5	CLCN5	CLCN5
Variant type	Large contiguous deletion	Nil	3-bp insertion	3-bp insertion	3 base pair insertion
Exons	3–15	NA	10	10	10
Zygosity	Hemizygous	NA	Hemizygous	Heterozygous	Hemizygous
Classification (ACMG)	Likely pathogenic		Pathogenic after segregation analysis (initially VUS)

↓ Table 2. Urine Beta2 Microglobulin and Genetic Analysis of Cases and Family Members

Case 1

Case 1 mother

Case 2

Case 2 mother

Case 2 maternal grandfather

ACMG: American College of Medical Genetics; bp: base pair; CES: clinical exome sequencing; SS: Sanger sequencing; NA: not applicable; VUS: variant of uncertain significance.

Urine spot beta2 microglobulin (normal < 300 ng/mL)

> 20,000

110

> 20,000

1,460

106 (post renal transplant)

Genetic study

CES

Gene

CLCN5

Variant type

Large contiguous deletion

Nil

3-bp insertion

3 base pair insertion

Exons

3–15

Zygosity

Hemizygous

Heterozygous

Hemizygous

Classification
(ACMG)

Likely pathogenic

Pathogenic after segregation analysis (initially VUS)

↓ **Table 3.** Frequency of Clinical Manifestations in DD1 [5–11]
Manifestations	Percentage
DD1: Dent disease type 1; LMWP: low-molecular-weight proteinuria.
LMWP	100
Hypercalciuria	44–90
Nephrocalcinosis	40–75
Nephrolithiasis	20–40
Aminoaciduria	20–50
Hypokalemia	20–40
Glucosuria	20–40
Hypophosphatemia	15–35
Metabolic acidosis	5–15
Incomplete Fanconi syndrome	25–65
Rickets	5–33

↓ Table 3. Frequency of Clinical Manifestations in DD1 [5–11]

Manifestations

Percentage

DD1: Dent disease type 1; LMWP: low-molecular-weight proteinuria.

LMWP

100

Hypercalciuria

44–90

Nephrocalcinosis

40–75

Nephrolithiasis

20–40

Aminoaciduria

20–50

Hypokalemia

20–40

Glucosuria

20–40

Hypophosphatemia

15–35

Metabolic acidosis

5–15

Incomplete Fanconi syndrome

25–65

Rickets

5–33