The child has a history of pharyngitis followed 10 days later by signs of glomerulonephritis. In this particular case, it is most probably a post-streptococcus glomerulonephritis which accounts for 80% of paediatric cases of glomerulonephritis.

The cells in the testes that secrete testosterone are the Leydig cells.Other cells in testes include:- Spermatogonia: These are undifferentiated male germ cells which undergo spermatogenesis in the seminiferous tubules of the testes.- Sertoli cells: They are a part of the seminiferous tubule of the testes, cells are activated by FSH and nourish developing sperm cells.- Myoid: They are squamous contractile cells which generate peristaltic waves, they surround the basement membrane of testes.- Fibroblasts: Cells which synthesise collagen and the extracellular matrix.

The most probable diagnosis for this patient is bilateral retractile testes. This a normal phenomenon in some pre-pubertal boys. Rationale:Testicular descent can continue until about 3-months of age. The pre-pubertal testis is small enough that with activation of the cremasteric reflex, they can enter the inguinal canal. This in itself is a normal finding providing the testis can be brought into the scrotum without tension and does not require surgical correction. With time the testis will lie within the scrotum. Orchidopexy for true undescended testis can be performed from 6-months of age. It is also warranted if the testes remain undescended or intra-abdominally leading to infertility.Other options:- An ascending testis is one, typically, following hernia or orchidopexy surgery that was in the testis but with time is within the inguinal canal and cannot be brought into the scrotum. Orchidopexy is required for this.- No surgery is required as when the testis enlarges with puberty it will remain within the scrotum.- The testes can be brought into the scrotum. Therefore they are not undescended.- The testes are retractile not ascending| ascending testis cannot be brought into the scrotum and would require orchidopexy.

E. coli accounts for the majority of UTI’s in children. If this child responds well to treatment and has no recurrence of his symptoms, then no form of imaging is required, as per NICE advice for children aged 6 months to 3 years. Had the child been less than 6 months of age, then a USS at 6 weeks would be necessary.Other options:- Pseudomonas causes atypical UTI. This warrants ultrasonography within the acute illness phase as it may reflect an underlying pathology and DMSA at 4-6 months.- Recurrent UTI is defined as two or more episodes of pyelonephritis OR 1 pyelonephritis and one cystitis OR 3 or more cystitis. It requires USS at six weeks and DMSA at 4-6 months.- Septicaemia is a sign of an atypical UTI. This requires USS within the acute illness as it may reflect an underlying pathology and DMSA at 4-6 months.- Unwell 48hrs post antibiotics is a sign of an atypical UTI. This requires USS within the acute illness as may reflect underlying pathology and DMSA at 4-6 months.

Vesicoureteric reflex (VUR) is described as the retrograde flow of urine from the bladder into the ureter due to an incompetent uterovesical junction. In primary VUR the lower urinary tract functions normally, while secondary VUR is associated with a poorly functioning lower urinary tract. The incidence of VUR is highest in new-born girls. They can present with hydronephrosis, or urinary tract infections.

The patient shows features of neurofibromatosis. The most likely cause for hypertension in this patient would be renal artery stenosis.Note:Neurofibromatosis is an inherited autosomal dominant disorder which could have affected this girl’s father, and she appears to have the classic skin lesions. A renal bruit might be heard in these patients. Polycystic kidney disease can occur in association with tuberous sclerosis, which also has skin lesions associated (different from those described in this patient). Most causes of hypertension in childhood have underlying renal causes, and a renal ultrasound with doppler is the first-line investigation of choice. Even if this is normal, further imaging would be indicated here, for example, isotope renal scans and angiography.

Using a Doppler device, you can estimate systolic BP even when the pulse is inaudible. Handheld and portable, the device uses ultrasound waves to detect the velocity of arterial blood flow. Helpful for patients with traumatic injuries or shock, the Doppler technique is also useful for children and patients whose BP is hard to hear because of oedema, obesity, vasoconstriction, or low cardiac output.

Von Hippel-Lindau syndrome is a genetic disorder inherited in autosomal dominant fashion. It is caused by the mutations of the VHL gene located on chromosome 3. The syndrome is characterized by the creation of multiple benign and malignant tumours involving various bodily systems along with the formation of numerous visceral cysts, including the renal and epididymal cysts. Down’s syndrome is associated with renal cysts, but it does not follow the autosomal dominant mode of inheritance, rather it is caused by non-disjunction of chromosome 21 during meiosis. Exomphalos is a defect of the medial abdominal wall leading to abnormal protrusion of abdominal viscera through it. It is not associated with renal cysts. Turner’s syndrome may be associated with renal cysts formation, but it is not transmitted in an autosomal dominant fashion. Polycystic kidney disease of childhood follows an autosomal recessive pattern of transmission.

Minimal change glomerulonephritis presents with mild or benign urinalysis findings. However, proteinuria together with the presence of oval fat bodies are typical.Minimal change glomerulonephritis (nephropathy) accounts for most cases of childhood nephrotic syndrome and 20–25% of adult nephrotic syndrome.

Based on the clinical presentation, the child probably has orthostatic proteinuria.Orthostatic proteinuria occurs when the kidneys can conserve urine when the patient is recumbent, such as sleeping at night, but leak protein with standing or in exercise. This results in early morning urine being negative for protein but late in the day urine being positive. It is mostly seen in tall thin adolescents and is benign. Other options:- Alport’s syndrome is a hereditary condition associated with haematuria and deafness. – Urinary tract infections can cause proteinuria, but leucocyte esterase and nitrites would also be expected in a child of this age. – Nephritic syndrome can be associated with proteinuria, but haematuria would also be present. – In nephrotic syndrome, proteinuria would be present on all occasions and associated with oedema.