Maple syrup urine disease (MSUD) is an autosomal recessive metabolic disorder affecting branched-chain amino acids. It is one type of organic academia. The condition gets its name from the distinctive sweet odour of affected infants’ urine, particularly prior to diagnosis, and during times of acute illness. MSUD, also known as branched-chain ketoaciduria, is an aminoacidopathy due to an enzyme defect in the catabolic pathway of the branched-chain amino acids leucine, isoleucine, and valine.

Classic Kallmann syndrome (KS) is due to isolated hypogonadotropic hypogonadism. Most patients have gonadotropin-releasing hormone (GnRH) deficiency, as suggested by their response to pulsatile GnRH therapy. The hypothalamic-pituitary function is otherwise normal in most patients, and hypothalamic-pituitary imaging reveals no space-occupying lesions. By definition, either anosmia or severe hyposmia is present in patients with Kallmann syndrome.

Infective endocarditis (IE) is an acute infective pathology of the endocardium secondary to some underlying cardiac pathology like VSD and TOF. Most commonly, it is bacterial in origin, caused by staphylococcus aureus in the majority of cases. Clinical features include fever, arthralgias, weight loss, anorexia, new-onset, or changing existing murmur. Skin manifestations include Osler’s nodes, Janeway lesions, splinter haemorrhages, and clubbing. Roth spots are conjunctival haemorrhages found in IE. Beau’s lines are not found in IE.

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.

Breast milk jaundice is a type of jaundice associated with breast-feeding. It typically occurs one week after birth. The condition can sometimes last up to 12 weeks, but it rarely causes complications in healthy, breast-fed infants. The exact cause of breast milk jaundice isn’t known. However, it may be linked to a substance in the breast milk that prevents certain proteins in the infant’s liver from breaking down bilirubin. The condition may also run in families. Breast milk jaundice is rare, affecting less than 3 percent of infants. When it does occur, it usually doesn’t cause any problems and eventually goes away on its own. It’s safe to continue breast-feeding.

Mumps presents with a prodromal phase of general malaise and fever. On examination there is usually painful parotid swelling which has high chances of becoming bilateral. In OM with effusion there are no signs of infection and the only symptom is usually hearing loss. Acute otitis externa produces otalgia as well as ear discharge and itching. Acute OM produces otalgia and specific findings upon otoscopy. In acute mastoiditis the patient experiences ear discharge, otalgia, headache, hearing loss and other general signs of inflammation.

The hypothalamus and pituitary gland control how much testosterone the testes produce and secrete. The hypothalamus sends a signal to the pituitary gland to release gonadotrophic substances (follicle stimulating hormone and luteinizing hormone). Luteinizing hormone (LH) stimulates testosterone production.

In older children who are able to have regular meal timings, the insulin regimen of choice is the basal-bolus regimen, which comprises a dose of long-acting insulin in combination with three doses of short-acting insulin. The dosage timings coincide with the meal times, ensuring greater flexibility and feasibility. The long-acting insulin serves to provide a stable glycaemic control. The other given regimens are suitable for younger children with a more irregular meal schedule.

While the clinical scenario and the anosmic presentation of the child are highly suggestive of Kallmann’s syndrome, reduced testosterone, FSH and LH levels can confirm the diagnosis.Kallman’s syndrome is a recognised cause of delayed puberty secondary to hypogonadotropic hypogonadism. It is usually inherited as an X-linked recessive trait. Kallman’s syndrome is thought to be caused by a failure of GnRH-secreting neurons to migrate to the hypothalamus.Clinical features of Kallmann’s syndrome include:- Delayed puberty- Hypogonadism, cryptorchidism- Anosmia- Low sex hormone levels – Inappropriately low/normal LH and FSH levels- Some patients can present with associated cleft lip/palate and visual/hearing defects.

The most probable diagnosis for this patient, according to the clinical scenario provided is tuberous sclerosis. It is an autosomal-dominant disorder characterised by hamartomas located throughout the body, often prominently involving the central nervous system and skin. Two loci on chromosomes 9 and 16 have been identified to be associated with this condition. The condition has a variable expression and penetrance and is further characterised by:- Seizures (usually infantile spasms)- Developmental delay- Facial/cutaneous angiofibromas (adenoma sebaceum)- Periungual fibromas (pink projections from the nail folds)- Shagreen patches (leathery thickenings of the skin usually on the back) – Ash leaf macules (areas of depigmentation that become visible under a Wood’s light)- Fundoscopy may reveal white streaks along the fundal vessels.