CMV infection is usually asymptomatic in adults. However, if the mother is infected for the first time during pregnancy then there is high chances of this infection passing on to the foetus. CMV infection can cause blindness, deafness, learning difficulties, restricted growth etc. Hepatitis B, herpes simplex, syphilis and HIV do not present with these classical signs of CMV infection in new-borns. It is estimated that 10 stillbirths occur in England and Wales every year due to CMV infection. The foetus is most at risk in early pregnancy. There is no effective prevention.

Unless given IV, a drug must cross several semipermeable cell membranes before it reaches the systemic circulation. Drugs may cross cell membranes by diffusion, amongst other mechanisms. The rate of diffusion of a substance is proportional to the difference in the concentration of the diffusing substance between the two sides of the membrane, the temperature of the solution, the permeability of the membrane and, in the case of ions, the electrical potential difference between the two sides of the membrane.

Toe walking refers to a pattern of walking in which the infants walk on the balls of their feet, without putting the heel of the feet on the ground. It is considered normal under the age of 2 years, but if it continues beyond that, it can signify some underlying pathology. The diseases that can be associated with toe walking include unilateral hip dislocation, Spinal tumours, Duchenne muscular dystrophy, prematurity, and cerebral palsy. Waardenburg’s syndrome is an autosomal dominant disorder, causing sensorineural deafness, and heterochromatic irises. Toe walking is not a feature.

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disease. The Lisch nodule represents one of the most common NF1 ocular manifestations.NF1 is caused by a genetic mutation which can cause tumours to grow on nerve endings| these cutaneous neurofibromas are benign tumours which grow on the skin, often first appearing during the hormonal changes that occur in teenage years. They vary in size and can appear anywhere on the body. The number of neurofibromas present differs greatly between individuals and over a lifetime Café au lait spots (coffee coloured birthmarks) are often the first and most common sign of NF1, and these are often found at birth and are usually evident by 2 years of age.Other features of NF1 can include Lisch nodules of the iris (small pigmentation in the iris which causes no disturbance to vision), skin-fold freckling (freckling/pigmentation in the groyne and armpits), plexiform neurofibromas (or sub cutaneous neurofibromas) which are diffuse tumours that grow along a nerve and are found in at least 25 % of people with NF1, optic gliomas (tumour of the optic nerve), and skeletal complications including pseudarthrosis and scoliosis. Macrocephaly (large head size) is also common, and short stature is found in around a third of people with NF1. Rare complications include a risk of malignancy, organs being compromised by neurofibromas, seizures, and hypertension.

The patient’s history points to absence seizures. Carbamazepine has been shown to aggravate generalized seizure types, especially absence seizures, because it acts directly on the ventrobasal complex of the thalamus which is critical to the neurophysiology of absence seizures.

Glandular fever (Infectious Mononucleosis) is caused by Epstein–Barr virus (EBV). Leucocytosis rules in infectious mononucleosis and thrombocytopenia is not an uncommon association. ESR is elevated in most of the cases. Paul-Bunnell test is a rapid test for infectious mononucleosis due to Epstein–Barr virus (EBV).

The endocardial cushions in the heart are the mesenchymal tissue that make up the part of the atrioventricular valves, atrial septum and ventricular septum. An incomplete fusion of these mesenchymal cells can cause an atrioventricular septal defect. The terms endocardial cushion defect, atrioventricular septal defect and common atrioventricular canal defect can be used interchangeably with one another.

The sensitivity of a screening test can be described in a variety of ways, typically such as sensitivity being the ability of a screening test to detect a true positive, being based on the true positive rate, reflecting a test’s ability to correctly identify all people who have a condition, or, if 100%, identifying all people with a condition of interest by those people testing positive on the test.The specificity of a test is defined in a variety of ways, typically such as specificity is the ability of a screening test to detect a true negative, being based on the true negative rate, correctly identifying people who do not have a condition, or, if 100%, identifying all patients who do not have the condition of interest by those people testing negative on the test.

The patient has bloody diarrhoea that sounds like a food poisoning in the clinical scenario. Campylobacter is the most common cause of this in the United Kingdom. This is then followed by Salmonella and Shigella. The symptoms are usually self limiting. This is more likely to be bacterial from the food than a viral gastroenteritis.

A supracondylar humerus fracture is a fracture of the distal humerus just above the elbow joint. The fracture is usually transverse or oblique and above the medial and lateral condyles and epicondyles. This fracture pattern is relatively rare in adults, but is the most common type of elbow fracture in children. They are historically associated with morbidity due to malunion, neurovascular complications, and compartment syndrome. Important arteries and nerves ( median nerve, radial nerve, brachial artery, and ulnar nerve) are located at the supracondylar area and can give rise to complications if these structures are injured. Most vulnerable structure to get damaged is Median Nerve. Damage/occlusion of the brachial artery is the cause of an absent radial pulse.

The most probable cause for the patient’s presentation would be intra-abdominal adhesions, and the most appropriate management for this patient would be nasogastric decompression and intravenous fluids.Malrotation typically presents in the first month of life with bilious vomiting. There is a lifetime risk of intra-abdominal adhesions. This presents with bilious vomiting and dilated bowel loops on plain abdominal film. 2/3 of adhesional obstructions resolve by conservative management with nasogastric decompression and intravenous fluids. If this fails to resolve after 24-48 hours or if there are signs of peritonism, a laparotomy is indicated.Other options:- Recurrent volvulus, urgent laparotomy required: The child is now 8-years-old and recurrent volvulus is unlikely as bowel should be fixed by intra-abdominal adhesions.- Intra-abdominal adhesions, surgery for division of intra-abdominal adhesions: Although surgery may be required, the majority of adhesional obstructive cases respond to conservative management.- Gastroenteritis with incompetent pylorus, intravenous fluids: While it is true that patients with malrotation can have bilious vomiting in gastroenteritis, the abdominal X-ray is suggestive of obstruction.- Likely sepsis with bilious vomiting, intravenous fluids and antibiotics: While a septic ileus can give bilious vomiting, this patient has no inflammatory markers suggestive of sepsis.

Hirschsprung’s disease is characterized by congenital absence of the autonomic plexus (Meissner’s and Auerbach’s plexus) in the intestinal wall. Usually limited to the distal colon, it can occasionally involve the entire colon or even the small bowel. There is abnormal or absent peristalsis in the affected segment, resulting in continuous spasm of smooth muscle and partial/complete obstruction. This causes accumulation of intestinal contents and dilatation of proximal segment. Skip lesions are highly uncommon. This disease is seen early in life with 15% patients presenting in first month, 60% by 1 year of age and 85% by the age of 4 years. Symptoms include severe and complete constipation, abdominal distension and vomiting. Patients with involvement of ultra-short segments might have mild constipation with intervening diarrhoea. In older children, symptoms include failure to thrive, anorexia, and lack of an urge to defecate. On examination, an empty rectum is revealed with stool palpable high up in the colon. If not diagnosed in time, it can lead to Hirschsprung’s enterocolitis (toxic megacolon), which can be fulminant and lead to death. Diagnosis involves a barium enema or a rectal suction biopsy. Barium enema shows a transition in diameter between the dilated, normal colon proximal to the narrowed, affected distal segment. It is to be noted that barium enema should be done without prior preparation, which can dilate the abnormal segment, leading to a false-negative result. A 24-hour post-evacuation film can be obtained in the neonatal period – if the colon is still filled with barium, there is a high likelihood of Hirschsprung’s disease. Full-thickness rectal biopsy is diagnostic by showing the absence of ganglion cells. Acetylcholinesterase staining can be done to highlight the enlarged nerve trunks. Abnormal innervation can also be demonstrated by rectal manometry.

Port-wine stains are a type of vascular birthmark caused by the abnormal development of capillaries in the skin. These pinkish-purplish discolorations present at birth and are associated with medical conditions such as Sturge-Weber syndrome, a neurocutaneous disorder involving the leptomeninges. Port wine stains are therefore associated with epilepsy, glaucoma or intellectual disability common in Sturge-Weber syndrome. Additional complications of Port wine stains include a loss of function if near the eye or mouth due to hypertrophy, or glaucoma if near the eyelid.

Ewing’s sarcoma is formed by small, round, blue cells, and is common in children. The usually develop in limbs, and clinical findings include pain and inflammation, with lytic destruction showing up on X-rays.

The management of cystic fibrosis requires a multidisciplinary approach, starting with a planned diet.The critical points of this management approach are:Chest physiotherapy and postural drainage – the parents are usually taught to do this.Deep breathing exercises,High calorie, high fat intake with vitamin supplementation.Pancreatic enzyme supplements with meals.Heart-lung transplantation would be the definitive treatment.Note: Previously, a high-calorie, low-fat diet was recommended to reduce steatorrhea. However, it is no longer the desired approach.

The characteristic cells in granulomatous inflammation are giant cells, formed from merging macrophages and epithelioid cells elongated with granular eosinophilic cytoplasm. Granulomatous reactions are seen in patients with tuberculosis. A tuberculous/caseating granuloma is characterised by a zone of central necrosis lined with giant multinucleated giant cells (Langhans cells) and surrounded by epithelioid cells, lymphocytes and fibroblasts. The caseous zone is present due to the damaged and dead giant cells and epithelioid cells.
Mast cells are only few in number and fibroblasts lay down collagen.
Basophils are not present.
The giant cell made up of macrophages are the most abundant cells in this inflammatory process.

The most likely cause of microcephaly in an asymptomatic 3-year-old child is congenital rubella syndrome.Microcephaly is defined as head circumference > two standard deviations below the mean.The causes of microcephaly include:- Genetic disorders: Down syndrome, Edward syndrome, Patau syndrome, Williams syndrome, Angelman syndrome, and Rett syndrome.- Infective: Meningitis, toxoplasmosis, CMV, rubella, varicella, HIVand Zika.- Acquired causes: Severe brain malformations, neurodegenerative diseases, hypoxic-ischemic injury, infarction, antenatal exposure to drugs, alcohol, and other toxins. Severe malnutrition and uncontrolled phenylketonuria in the mother are other causes of microcephaly in children.- Craniosynostosis- Neurometabolic disorders- Early non-accidental trauma- Fanconi anaemia- Other causes include: Familial and nonfamilial nonsyndromic microcephalyMost children with microcephaly have one or several associated symptoms:- Developmental delay- Seizures- Visual abnormalities- Short stature

Breath-holding spells are usually caused by either a change in the child’s breathing or a slowing of the heart rate. In some children, breath-holding spells may be related to iron deficiency anaemia, a condition in which the body doesn’t produce a normal number of red blood cells. Conclusion: Not only Iron deficiency anaemia but also iron deficiency alone without anaemia is associated with a risk of high-frequency cyanotic breath holding spells. Iron therapy results in reduction in spells’ frequency which was correlated with increasing ferritin and iron levels.

Box plots can be used to display numerical outcomes and give valid summaries (median and interquartile range or IQR) for any distributional form that the outcomes might take. Additionally, they show outlying values and provide data summaries that are not unduly influenced by those outliersOther options:- The box itself represents the interquartile range, with the two whiskers representing the variability outside the upper and lower quartiles.- Variability is represented with whiskers and feathers are used in fan charts.They are not as informative as showing the actual values but can be used to make comparisons of medians and IQRs between subgroups.

The patient history suggests a spontaneous tension pneumothorax which is a life-threatening situation in which excess air is introduced into the pleural space surrounding the lung. When there is a significant amount of air trapped in the pleural cavity, the increasing pressure from this abnormal air causes the lung to shrink and collapse, leading to respiratory distress. This pressure also pushes the mediastinum (including the heart and great vessels) away from its central position, e.g. deviated trachea, and diminishing the cardiac output. Tension pneumothoraxes cause chest pain, extreme shortness of breath, respiratory failure, hypoxia, tachycardia, and hypotension. These are definitively managed by insertion of a chest tube. However, in the emergency setting temporizing measures are needed while chest tube materials are being gathered. In these situations, urgent needle thoracostomy (also called needle decompression) is performed.

Adenoid tissue sometimes swell as a result of fighting off the infection as germs are trapped in the adenoids. Adenoid enlargement is suspected.

Liddle’s syndrome,  is an autosomal dominant disorder, that is characterized by early, and frequently severe, high blood pressure associated with low plasma renin activity, metabolic alkalosis, low blood potassium, and normal to low levels of aldosterone. Liddle syndrome involves abnormal kidney function, with excess reabsorption of sodium and loss of potassium from the renal tubule. Bartter Syndrome also presents with hypokalaemia, however blood pressure of these patients is usually low or normal.

Among the treatment options provided, the most appropriate would be prednisolone 1-2 mg/kg.Other options:- Dexamethasone 0.15 mg per kg is the correct dose based on new trials and BNF guidance.- Inhaled budesonide 2mg would be a more appropriate dose.- Nebulised adrenaline may also be used.Croup:Laryngotracheobronchitis caused most commonly by parainfluenza virus. It most commonly affects children between 6 months to 3 years.Seasonal peaks: Most prevalent in autumn and spring.It starts as viral URTI then progresses to barking cough and a hoarse cry. Stridor and respiratory distress may occur. The illness can last from two days to 2 weeks.Relevant differential diagnoses include epiglottitis (the child will be septic with high temp and drooling) and inhaled foreign body.All children with moderate/severe croup should be given one dose of oral dexamethasone.Further doses may be needed if children have rebound symptoms.

Among the given options, pituitary adenoma is an acquired anterior pituitary disorder which represent between 10 and 25% of all intracranial neoplasms.Other options:- Agenesis of the corpus callosum is characterised by the partial or complete absence of the corpus callosum. This condition is associated with pituitary hormone deficiencies.- Congenital disorders such as hydrocephalus or arachnoid cysts may be a cause of precocious puberty.- Pituitary hypoplasia and septo-optic dysplasia are congenital disorders of the pituitary gland.

Patients with HIV have a deficiency of CD4 lymphocytes which are also known as helper T cells (Th). They are involved with antigen-specific responses as well as delayed-type hypersensitivity. The risk of developing P. jiroveci pneumonia is greatest with a CD4 count of 200 x 109/l or below.

Cases of neonatal infant ambiguous genitalia can be a great source of psychological stress for families. One of the most important next steps in managing the case is reassuring the parents that the best care will be given to the baby and then informing them about the investigations that will need to be performed before a sex can be assigned. The sex should not be guessed just by examination nor assigned by karyotyping. Thorough investigations must be completed with the help of endocrinologists for the best outcome.

NICE guidelines suggest that when a child’s single risk factor is 2 vomits, the child should be observed for 4 hours from the time of the injury, instead of having a CT.

Vitamin A is a fat-soluble compound occurring in various forms. The RDA for 0-12 months old babies is 400-600micrograms/day. Most of the vitamin A is stored in the liver, making animal liver an excellent source of vitamin A. Vitamin A deficiency is characterized by the deposits of keratin in the conjunctiva, known as Bitot’s spots, keratomalacia, night blindness, and anaemia.Vitamin A toxicity or excess is characterized by hyperkeratosis, hypothyroidism, hypo/hyperpigmentation, etc.According to WHO guidelines, children under two years of age who develop measles should be given two additional doses of vitamin A supplementation 24 hours apart, which is necessary for preventing eye damage, blindness, and reducing mortality by 50%.

In this case, the affected individuals are all heterozygotes. Therefore, the mutation is autosomal dominant. Also, the mother does not carry the mutation, further confirming the autosomal dominant nature of the disease, which is most probably achondroplasia.

Key observations in the results:

1. Oxygen Saturation Step-Up:
   • There is a significant step-up in oxygen saturation from the right ventricle (72%) to the pulmonary artery (86%). This suggests the presence of left-to-right shunting of blood.
2. Pressure Differences:
   • The pressure in the pulmonary artery is elevated (53/13 mmHg), indicating pulmonary hypertension.

Differential Diagnosis:

1. Patent Ductus Arteriosus (PDA):
   • PDA can cause increased pulmonary blood flow, leading to a step-up in oxygen saturation in the pulmonary artery. The pulmonary artery pressures can also be elevated due to increased blood flow.
2. Primary Pulmonary Hypertension:
   • Typically presents with elevated pulmonary pressures but does not usually show a step-up in oxygen saturation.
3. Pulmonary Stenosis:
   • Would result in elevated right ventricular pressure but would not explain the step-up in oxygen saturation.
4. Septum Primum Atrial Septal Defect (ASD):
   • Would result in a step-up in oxygen saturation from the right atrium to the right ventricle, not between the right ventricle and pulmonary artery.
5. Tetralogy of Fallot:
   • Characterized by right ventricular outflow tract obstruction, VSD, right ventricular hypertrophy, and an overriding aorta. Oxygen saturation levels would typically be lower in the systemic circulation.