Types of DNA mutations and their impactpoint mutation:Substitution: One base is incorrectly added during replication and replaces the pair in the corresponding position on the complementary strand as in Sickle cell anaemiaInsertion: One or more extra nucleotides are inserted into replicating DNA, often resulting in a frameshift as in one form of beta-thalassemiaDeletion: One or more nucleotides is skipped during replication or otherwise excised, often resulting in a frameshift as in Cystic fibrosis.Chromosomal mutation:Inversion: One region of a chromosome is flipped and reinserted as in Opitz-Kaveggia syndromeDeletion: A region of a chromosome is lost, resulting in the absence of all the genes in that area as in Cri du chat syndromeDuplication: A region of a chromosome is repeated, resulting in an increase in dosage from the genes in that region as in some cancers and Charcot-Marie toothTranslocation: A region from one chromosome is aberrantly attached to another chromosome as in One form of leukaemiaCopy number variation:Gene amplification: The number of tandem copies of a locus is increased as in Some breast cancersExpanding trinucleotide repeat: The normal number of repeated trinucleotide sequences is expanded as in Fragile X syndrome, Huntington’s disease

CMPI ( cow’s milk protein intolerance) is an immunological reaction to one or more of the many proteins found in cow’s milk. It may be IgE mediated or non-IgE mediated. The prominent signs and symptoms include sneezing, rhinorrhoea, coughing, wheezing, oral angioedema, oral itching, diarrhoea, vomiting, and bloody stools. Steatorrhea is not a recognized feature of CMPI.

A three-year child’s typical developmental milestones include walking up and down the stairs with alternating feet, jumping in a place with two feet together, and jumping forward for about 2 feet. The child can pedal a tricycle and can throw a ball over and underhand. An average child should start walking around 12-14 months of age and should be investigated as early as 18 months if they do not begin to walk. Skipping can be done by a child of 5 years of age. A child of 6-7 years of age can ride a bike with stabilizers and can balance on one foot for 20 seconds.

Among the options provided, an 8-week-old full-term infant with normal developmental milestones will smile in response to appropriate stimuli.Rationale:Smiles in response to appropriate stimuli are seen from around 6 weeks of age. A social smile, where the infant has an awareness that a smile attracts attention, is not observed until around 3 months of age.Other options:- At 6 weeks an infant is able to follow objects in the horizontal plane through 90 deg; fixing and following an object through 180 deg in the horizontal plane is a milestone achieved at 3 months, as is pushing up onto forearms. – Pushing up onto hands occurs by around 5 months.- Infants of 3 months should startle to a 60 dB sound.

The most probable diagnosis for this patient’s symptoms is psoriasis. Psoriasis:Chronic plaque psoriasis is characterised by pinkish-red hyperkeratotic plaques, which occur mainly on extensor surfaces such as knees and elbows. The lower back, ears and scalp can also be involved. Koebner phenomenon: Psoriasis typically exhibits this phenomenon where new plaques of psoriasis occur particularly at sites of skin trauma. Diagnosis:Skin biopsy of psoriatic plaques reveals acanthosis and parakeratosis, reflecting increased skin turnover. Capillary dilatation within the dermis also occurs, surrounded by a mixed neutrophilic and lymphohistiocytic perivascular infiltrate.

Except Tetralogy of Fallot, the others are acyanotic heart diseases. The cyanotic spells and loss of consciousness are due to spasm of the infundibular septum, which acutely worsens the right ventricular outflow tract obstruction. The given murmur is due to a ventricular septal defect.

The lingual nerve wraps around Wharton’s duct, and thus, is at risk of injury as the submandibular gland is mobilised. The lingual nerve provides sensory supply to the anterior 2/3 of the tongue.Note:- Submandibular duct (Wharton’s duct): It opens lateral to the lingual frenulum on the anterior floor of the mouth. It is around 5 cm in length.- Lingual nerve wraps around Wharton’s duct. As the duct passes forwards, it crosses medial to the nerve, above it and then crosses back, lateral to it, to reach a position below the nerve.

Umbilical hernias are common in young children and they carry a low risk of incarceration as compared to inguinal hernias. About 90% umbilical hernias resolve by the age of 4 years. The best management for young children is to wait for resolution without surgical repair, unless there are complications. Parents should be assured that the child does not need to be referred to the general surgeon, nor should any home remedies such as taping a coin over the hernia be encouraged. If after the age of 4 it has not resolved, then surgery is indicated. This also applies to girls to prevent an unsightly hernia should she get pregnant.

From the given scenario, the extraocular muscle affected in the child is superior oblique muscle. Point to remember:All of the extraocular muscles are supplied by the oculomotor nerve (3rd cranial nerve), except superior oblique (trochlear nerve/4th cranial nerve) and lateral rectus (abducens nerve/6th cranial nerve).The superior oblique muscle causes the eye to move downwards and medially. The unopposed inferior oblique, in this case, causes the eye to deviate upwards and medially. Children tend to tilt their head (torticollis) to the side opposite to the affected eye with their chin down toward the shoulder, and their face turned away from the affected side to decrease the diplopia.

Stevens-Johnson syndrome (SJS) is a type of severe skin reaction. The most common cause is certain medications such as lamotrigine, carbamazepine, allopurinol, sulphonamide antibiotics, and nevirapine.

The most appropriate next step in the management would be to refer the patient for an ENT opinion. Rationale:This child has clinical signs of adenotonsillar hypertrophy, symptoms of persistent snoring and features of obstructive sleep apnoea (OSA). Suspected OSA warrants referral to an ENT specialist. Other options:- Capillary blood gas: The investigation consists of overnight oxygen saturation monitoring or polysomnography.- Chest X-ray: A chest x-ray is not indicated.- Phenoxymethylpenicillin (Penicillin V) is the first-line treatment for tonsillitis. However, with a history of several months and no suggestion of fever or sore throat, acute tonsillitis is unlikely.- Weight loss advice: Obesity is a risk factor for obstructive sleep apnoea (OSA) amongst other health problems. The child’s weight should be highlighted and advice and support for weight loss provided however referral to ENT is warranted for further investigation.

Fertilization occurs when the sperm reaches an egg released during ovulation. At the time of fertilization, the interaction of sperm with the zona pellucida stimulates the release of calcium. This process initiates a corona reaction that prevents polyspermy.

The prognosis for croup is excellent, and recovery is almost always complete with complications being quite rare. The possible complications are pneumonia, bacterial tracheitis, pulmonary oedema, pneumothorax, pneumomediastinum, lymphadenitis or otitis media. Bacterial tracheitis is a life-threatening infection that can arise after the onset of an acute viral respiratory infection.

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.

Benign neonatal sleep myoclonus (BNSM) is a disorder commonly mistaken for seizures during the new-born period. It is characterized by myoclonic lightninglike jerks of the extremities that exclusively occur during sleep; it is not correlated with epilepsy.Causes of neonatal seizures:Hypoxic-ischemic encephalopathy: Hypoxic-ischemic encephalopathy disrupts the ATP-dependent sodium-potassium pump and appears to cause excessive depolarization.Intracranial haemorrhage: occurs more frequently in premature than in term infants. Subarachnoid haemorrhage is more common in term infants. This type of haemorrhage occurs frequently and is not clinically significant. Typically, infants with subarachnoid haemorrhage appear remarkably well. Metabolic disturbances include hypoglycaemia, hypocalcaemia, and hypomagnesemia. Less frequent metabolic disorders, such as inborn errors of metabolism, are seen more commonly in infants who are older than 72 hours. Typically, they may be seen after the infant starts feeding.Intracranial infections (which should be ruled out vigorously) that are important causes of neonatal seizures include meningitis, encephalitis (including herpes encephalitis), toxoplasmosis, and cytomegalovirus (CMV) infections. The common bacterial pathogens include Escherichia coli and Streptococcus pneumoniae.Cerebral malformationsBenign neonatal seizures

Kaposi varicelliform eruption (KVE) is the name given to a distinct cutaneous eruption caused by herpes simplex virus (HSV) type 1, HSV-2, coxsackievirus A16, or vaccinia virus that infects a pre-existing dermatosis. Most commonly, it is caused by a disseminated HSV infection in patients with atopic dermatitis (AD) and, for this reason, is often referred to as eczema herpeticum (EH).Kaposi varicelliform eruption (KVE) is now known to occur in children of any age and in adults, however, most patients (56%) are aged 15-24 years.

Cluster headaches present with unilateral severe headache that may be associated with ipsilateral cranial autonomic symptoms including; lacrimation, rhinorrhoea, ophthalmic injection, and occasionally, Horner syndrome (ipsilateral miosis, ptosis, and facial anhidrosis).

The Glasgow Coma Scale, being inappropriate for use in children (especially below the age of 5) as they are unable to elicit the verbal response as per the adult GCS. Therefore, GCS for the paediatric age group was modified to Adelaide coma scale (ACS), which is stated as follows:Best Eye Response (as in adult scale):Spontaneous – 4To speech – 3To pain – 2No response – 1Best Verbal Response:Oriented – 5Words – 4Vocal sounds – 3Cries – 2No response – 1Best Motor Response (as in adult scale):Obeys commands – 5Localises pain – 4Flexion to pain – 3 Extension to pain – 2No response – 1 The described child scores:Eye response – 1; Verbal response – 3; Motor response – 4Thus, bringing the total ACS score to 8.

The femoral artery is the one accompanying the femoral shaft, being the most important blood supplier of the leg. Femoral artery injury during a femur shaft fracture is quite common as a result of blunt trauma.

Based on the clinical scenario provided, the most probable nerve injured in this patient would be the trochlear nerve. The trochlear nerve has a relatively long intracranial course, and this makes it vulnerable to injury in head trauma. Head trauma is the most frequent cause of acute fourth nerve palsy. A 4th nerve palsy is the most common cause of vertical diplopia. The diplopia is at its worst when the eye looks medially which it usually does as part of the accommodation reflex when walking downstairs.

Precocious Puberty is the development of secondary sexual characteristics before the age of 8 in females, and 9 in males. The first sign of early puberty in males is testicular enlargement, followed by growth of the penis and the scrotum at least a year after. Precocious puberty in boys in uncommon and usually has an organic cause leading to excess secretion of testosterone. These can be gonadotrophin dependent in the case of an inter cranial lesion, where the testes would be bilaterally enlarged, or from excess production from the adrenal gland in the case of adrenal hyperplasia or a tumour.

Among the provided options, we would expect a normally developing six-month-old child to have lost Moro’s reflex.Note:The Moro reflex is present from birth and persists until 4 months of age. It is abnormal for the Moro reflex to persist much beyond this stage, and if it does, cerebral palsy should be considered.A normal 6-month old baby should be able to roll over from front to back, readily follow objects with their eyes, transfer objects from hand to hand, recognise parental voices and babble and laugh.Other options:- Having a pincer grip is more typical of a 9-12-month-old.- Although at 6 months babies are often able to sit briefly or with support, sitting steadily is typically seen at 9 months.- Starting to stand with support is more typical of a 9-12-month-old.- Waving bye-bye is more typical of a 9-12-month-old.

Tuberous sclerosis is an autosomal dominant neurocutaneous condition associated with increased psychiatric co-morbidity. It results from the mutation of TSC1 or TSC2 tumour suppressor genes. Multiple benign tumours of the brain and other vital organs are characteristic of this disease. Important findings include subependymal nodules, bone cysts, cardiac rhabdomyoma, and learning difficulties. Lisch nodules of the iris occur in neurofibromatosis.

Answer: Do not operate and review the patient several weeks laterAir weapon injuries in children should be managed in the same way as any low velocity gun shot injury. Subcutaneous pellets are best removed. Urgent specialist referral is indicated for cranial, ocular, chest, abdominal, or vascular injuries as they may require emergency surgery. Cardiac injuries may be rapidly fatal. Penetrating abdominal injuries involving hollow viscera or major blood vessels need prompt exploration and repair. Intracranial air weapon pellets should be removed if possible. A pellet in lung parenchyma or muscle may be safely left in situ but there is a risk of infection. A pellet that has penetrated a joint or is associated with a fracture requires skilled orthopaedic management. A pellet lodged near a major blood vessel or nerve should ideally be removed. The possibility of intravascular embolism must be considered if the pellet is absent from a suspected entry site and there is no exit wound; numerous examples of arterial and venous embolism of an air weapon pellet in children have been described.In this case, the child seems well so there is no need to operate. He should be reviewed several weeks later.

Breast milk jaundice is thought to be associated with one or more abnormalities in the maternal milk itself. Breast milk jaundice syndrome generally needs no therapy if serum bilirubin concentrations remain below 270 mmol/l in healthy full-term infants. When the serum bilirubin concentration is above 270 mmol/l and rising, temporary interruption of breastfeeding may be indicated.

The primary intestinal loop is formed from the midgut which gives rise to the distal half of the duodenum, the jejunum, ascending colon, proximal two thirds of the transverse colon and the ileum.

The rational part of a teen’s brain isn’t fully developed until the age of 25 or so.In fact, recent research has found that adult and teen brains work differently. Adults think with the prefrontal cortex, the brain’s rational part. This is the part of the brain that responds to situations with good judgment and an awareness of long-term consequences. Teens process information with the amygdala. This is the emotional part.

Immunoglobulin G (IgG) glomerular immune deposits are seen more commonly in HSP compared to IgA nephropathy.The presentation of the child is highly suggestive of Henoch-Schonlein purpura (HSP). It is an IgA-mediated, autoimmune hypersensitivity vasculitis that targets the small vessels of the skin, GI tract, kidneys, and joints.It is most commonly seen in children aged 3 – 6years and is twice as common in boys than girls. Preceding viral URTI with low-grade pyrexia is common. The most common organism associated with HSP is, however, Group A streptococcal infection A.A purpuric rash is seen on the back of the legs and buttocks and can less frequently, affect the arms. Arthralgia is common (usually knees/ankles) in these patients. Abdominal pain and bloody diarrhoea may occur. And half of the children with HSP have renal involvement. Rarely, it can lead to end-stage renal failure.Treatment includes adequate hydration, occasionally steroids, and other immunosuppressants. The disease can recur in 1 in 3 children.

Fine motor development involves greater use of the hands to perform more precise tasks. By 6 -12 months children should be able to reach for small objects and pass an object from one hand to the other. From 1 -2 years they can perform more complex tasks such a building a tower of blocks, feeding themselves, and turning knobs. In terms of pencil skills, they should be able to imitate scribbles and then spontaneously scribble. By the age of 2 years they can draw a line, and by three they can draw a circle. From the age of 3.5 they can draw a cross, 4.5 – a square, 5 – a triangle, and 6 a diamond.

Based on the clinical scenario provided, the most probable diagnosis is Peutz-Jeghers syndrome.Peutz-Jeghers syndrome is an autosomal dominant condition characterised by numerous hamartomatous polyps in the gastrointestinal tract. It is also associated with pigmented freckles on the lips, face, palms and soles.Genetic basis: It follows an autosomal dominant inheritance, and the gene responsible encodes serine-threonine kinase LKB1 or STK11.Classical features of PJS include:- Hamartomatous polyps in the GI tract (mainly small bowel)- Pigmented lesions on lips, oral mucosa, face, palms and soles- Intestinal obstruction, e.g. intussusception- Gastrointestinal bleedingThe treatment is mainly conservative unless complications develop.Note:Hereditary haemorrhagic telangiectasia can also be associated with mucocutaneous lesions and iron-deficiency anaemia, but intestinal polyps are not a feature.