The most important test recommended among the given options is the measurement of creatine kinase levels.The child presents with a gross motor developmental delay, and multiple investigations can be undertaken to confirm the diagnosis. However, the clinching point in the given clinical scenario is the presence of a positive Gower’s sign.Gower’s sign is an excellent screening test for muscle weakness, which is typically observed as an early clinical feature of Duchenne muscular dystrophy (DMD).Creatinine kinase measurement is an easy and rapid test to aid in the diagnosis. Early diagnosis has significant implications not only for the child but for the family, particularly for genetic counselling. DMD is an X-linked recessive disorder, with an abnormal gene at the X chromosome at the Xp21 locus. It is a progressive degenerative muscular condition where muscle fibres are replaced by fat and fibrosis (i.e., become dystrophic).

Pityriasis amiantacea: This condition is characterized by thick, asbestos-like scales on the scalp and is often associated with psoriasis or seborrheic dermatitis.

Infantile seborrhoeic dermatitis: Also known as cradle cap, this condition causes greasy, yellowish scales on the scalp.

Tinea capitis: A fungal infection of the scalp that leads to scaling, hair loss, and sometimes redness and swelling.

Cutaneous lupus erythematosus: While lupus can cause skin lesions, it is less commonly associated with a scaly scalp compared to the other conditions listed. It can cause hair loss and erythema, but significant scaling is not a primary feature.

Scalp psoriasis: This condition is well-known for causing thick, silvery scales on the scalp

The presence of anti-endomysial antibodies confirms the diagnosis of Celiac disease, which is the primary cause of illness in this patient. The sweat chloride test is performed with cystic fibrosis.

Certain CHDs may present with a differential cyanosis, in which the preductal part of the body (upper part of the body) is pinkish but the post ductal part of the body (lower part of the body) is cyanotic, or vice versa (reverse differential cyanosis). The prerequisite for this unique situation is the presence of a right-to-left shunt through the PDA and severe coarctation of the aorta or aortic arch interruption or severe pulmonary hypertension. In patients with severe coarctation of the aorta or interruption of the aortic arch with normally related great arteries, the preductal part of the body is supplied by highly oxygenated pulmonary venous blood via the LA and LV, whereas the post ductal part is supplied by deoxygenated systemic venous blood via the RA, RV, main pulmonary artery (MPA) and the PDA. In the new-born with structurally normal heart, a differential cyanosis may be associated with persistent pulmonary hypertension of the new-born. In the cases of TGA with coarctation of the aorta or aortic arch interruption, the upper body is mostly supplied by systemic venous blood via the RA, RV, and ascending aorta, whereas the lower body is supplied by highly oxygenated pulmonary venous blood via the LA, LV, MPA, and then the PDA. For accurate detection of differential cyanosis, oxygen saturation should be measured in both preductal (right finger) and post ductal (feet) parts of the body.

Croup is the most common aetiology for hoarseness, cough, and onset of acute stridor in febrile children. Symptoms of coryza may be absent, mild, or marked. The vast majority of children with croup recover without consequences or sequelae.

Observational studies fall under the category of analytic study designs and are further sub-classified as observational or experimental study designs. The goal of analytic studies is to identify and evaluate causes or risk factors of diseases or health-related events. The differentiating characteristic between observational and experimental study designs is that in the latter, the presence or absence of undergoing an intervention defines the groups. By contrast, in an observational study, the investigator does not intervene and rather simply “observes” and assesses the strength of the relationship between an exposure and disease variable.Three types of observational studies include cohort studies, case-control studies, and cross-sectional studies. Case-control and cohort studies offer specific advantages by measuring disease occurrence and its association with an exposure by offering a temporal dimension (i.e. prospective or retrospective study design). Cross-sectional studies, also known as prevalence studies, examine the data on disease and exposure at one particular time point. Because the temporal relationship between disease occurrence and exposure cannot be established, cross-sectional studies cannot assess the cause and effect relationshipDisadvantage of Cohort study is Susceptible to selection bias.

Pityriasis rosea is a common, acute exanthem of uncertain aetiology. Viral and bacterial causes have been sought, but convincing answers have not yet been found. Pityriasis rosea typically affects children and young adults. It is characterized by an initial herald patch, followed by the development of a diffuse papulosquamous rash. The herald patch often is misdiagnosed as eczema. Pityriasis rosea is difficult to identify until the appearance of characteristic smaller secondary lesions that follow Langer’s lines (cleavage lines). Several medications can cause a rash similar to pityriasis rosea, and several diseases, including secondary syphilis, are included in the differential diagnosis. Typically, only symptomatic treatment of pruritus with lotions, oral antihistamines, and/or a short course of topical steroids is necessary.

The patient is suffering from an anaphylactic reaction to the cashew nut he consumed.Anaphylaxis:Anaphylaxis is an acute, rapidly progressing, potentially life-threatening IgE mediated Type I hypersensitivity reaction.It involves the release of mediators from mast cells, basophils and inflammatory cells. It is characterised by oedematous swelling of the airway mucosa giving rise to dyspnoea and respiratory distress.The most common cause of anaphylaxis in children is a food allergy.Risk factors for death in patients with anaphylaxis include asthma, age 11+, peanut allergy, and delay in adrenaline administration.Management of anaphylaxis includes:- Resuscitation – ABCD- Remove the allergen- IM adrenaline is given at ten microgram/kg or Nebulised adrenaline 5ml 1:1,000- IV Hydrocortisone is given at 4mg/kg- pro re nata IV fluid support. – Followed by observation.

The patient’s clinical presentation is highly suggestive of Charcot–Marie–Tooth syndrome.It is a hereditary sensory and motor neuropathy. It is also the commonest cause of inherited peripheral neuropathy. The lower motor neuron signs are usually mild in childhood, the age of onset is very variable, and the distal weakness can take years to progress. It is not fatal and does not affect the normal life expectancy.

When a child with joint problems presents with red-eye, the likelihood of anterior uveitis must be excluded by involving an ophthalmologist in the assessment. This is because uveitis is the most common extra-articular manifestation of juvenile idiopathic arthritis.Other options:- Cataract: It does not give rise to a red-eye, but leukocoria. Often this would have been picked up at an earlier age. – A patient with a corneal foreign body almost would almost invariably give a suspicious history (onset while playing outdoors etc.), as well as have marked symptoms of ocular discomfort (red, watery and painful eyes). – A child with periorbital cellulitis often presents acutely unwell and distressed. – A child with an uncorrected refractive error often complains of being unable to see in class and does not normally present with ocular redness.

The most probable diagnosis based on the scenario provided above is hereditary spherocytosis.While jaundice and abdominal pain might make you think of hepatitis or cholecystitis in the first instance, the lack of fever suggests otherwise. The apyrexial presentation is against acute cholecystitis, and the past medical history reveals a chronic type of fatigue and two previous episodes of hepatitis. Furthermore, it is unlikely that the child has contracted infective hepatitis twice and now a third time! The most common cause of hepatitis in childhood is hepatitis A, however the lack of travel history to endemic areas makes this less likely. Hepatitis A is usually a mild, self-limiting disease that never presents with chronic symptoms. The chronicity of his fatigue and the blood results lead towards a haematological diagnosis. This is further substantiated by his low haemoglobin levels, high MCV and high reticulocyte count. Chronic haemolytic anaemia is the most likely cause, and the negative Coombs excludes autoimmune haemolytic anaemia (AIHA). Thus, leaving us with the answer as hereditary spherocytosis.Hereditary spherocytosis is a disorder that makes the cytoskeleton of red cells more fragile and therefore leads to red cell death and splenomegaly. Gallstones are a result of this red cell destruction and increased haem metabolism.

Marfan syndrome is a disorder that affects the connective tissue in many parts of the body. Connective tissue provides strength and flexibility to structures such as bones, ligaments, muscles, blood vessels, and heart valves. The signs and symptoms of Marfan syndrome vary widely in severity, timing of onset, and rate of progression.This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.At least 25 percent of Marfan syndrome cases result from a new mutation in the FBN1 gene. These cases occur in people with no history of the disorder in their family.The two primary features of Marfan syndrome are vision problems caused by a dislocated lens (ectopia lentis) in one or both eyes and defects in the large blood vessel that distributes blood from the heart to the rest of the body (the aorta).Associations include:Tall statureLearning disability (50%)Lens subluxation (usually upwards)Femoral herniaHemivertebraeCardiac problems (Aortic/mitral regurgitation, aneurysms)Joint hypermobilityArachnodactyly

Based on the studies, genetic factors are responsible for approximately 60 % DVT cases. Factor V (FV) Leiden which is the most common cause of inherited thrombophilia, predisposes patients to DVT because of resistance to protein C.The heritable causes of deep vein thrombosis, from most to least common are:Factor V LeidenProthrombin G20210A variantProtein C deficiencyProtein S deficiencyAntithrombin deficiencyVon Willebrand disease and thalassaemia are not causes of DVT.

Possible Zika virus infections have been identified in breastfeeding babies, but Zika virus transmission through breast milk has not been confirmed. Additionally, we do not yet know the long-term effects of Zika virus on young infants infected after birth. Because current evidence suggests that the benefits of breastfeeding outweigh the risk of Zika virus spreading through breast milk, CDC continues to encourage mothers to breastfeed, even if they were infected or lived in or travelled to an area with risk of Zika.

Administration of IV prostaglandin/PGE1 (e.g., alprostadil) is indicated in ductal-dependent CHDs until surgery can be performedMechanism: prostaglandin prevents the ductus arteriosus from closing → creates intentional shunt to allow mixing of deoxygenated with oxygenated blood.

In case control studies, observational studies are made to compare two groups, individuals with a certain condition, to those without the condition, with all other factors being equal. In the situation presented by the question, the study was to determine whether a prior risk factor, a low birth weight, was associated with later developing adolescent hypertension, using a paired t-test to statistically determine whether there was indeed a significant association between the two conditions. Case control studies only help to draw associations between two groups and therefore cannot indicate causation. In this scenario we are also not given the p value to determine whether the association is statistically significant. Therefore there is not enough evidence to conclude whether or not birthweight affects the development of adolescent hypertension.

The clinical picture suggests that the baby has Beckwith-Wiedemann Syndrome, which predisposes the individual to cancer. The most common childhood tumour that a person with Beckwith-Wiedemann Syndrome may develop is Wilms’ tumour. Typical features include: macrosomia, asymmetric limb growth, macroglossia, neonatal hypoglycaemia, umbilical hernias or other abdominal wall deformities.

Diarrhoea is defined as having three or more loose or liquid stools per day, or as having more stools than is normal for that person. Severe diarrhoea, causing fluid loss and loss of bicarbonate, will result in marked dehydration and metabolic acidosis.

A Mongolian spot can be present in new born babies which usually appears over the back and fades with time. There is nothing to worry about.

Laxatives have been shown to be beneficial in the treatment of chronic childhood constipation. Studies have shown that polyethylene glycol, mineral oil, magnesium hydroxide, and lactulose are effective and can be used for a prolonged periods without risk.

The study described in the question is a ‘cohort’ study.Other options:A prospective observational study – When groups are classified according to one or more factors at a given time and followed forward to determine outcomes (usually some health status)- Although there is in one sense a control group (those who do not develop the health problem), this is not generally called a ‘controlled’ trial. – An ecological study would look at outcomes in different groups (countries or regions usually) who follow different practices.

When topical agents are insufficient or not tolerated, or in cases of moderate to severe acne, especially when the chest, back and shoulders are involved, systemic antibiotics are often considered the next line of treatmentSystemic antibiotics should not be used to treat mild acne because of the risk of increasing resistance. The additional use of nonantibiotic topical agents in combination with oral antibiotics should be considered. Topical retinoids with oral antibiotics may give a faster response and be more effective than either drug used alone.Treatment with tetracyclines and erythromycin reduces P. acnes within the follicles, thereby inhibiting the production of bacterial-induced inflammatory cytokines. These agents also have inherent anti-inflammatory effects, such as suppressing leukocyte chemotaxis and bacterial lipase activity.

The drainage of cerebral spinal fluid from the third ventricle to the fourth ventricle is carried out by the cerebral aqueduct. The cerebral aqueduct is the narrowest passageway in the entire ventricular system and thus forms the most common site of blockage of flow of cerebrospinal fluid. The interventricular foramen allows passage of CSF to the third ventricle. The foramen of Luschka and Magendie are located on the fourth ventricle and allow passage of CSF to the subarachnoid space from the ventricular system. The pontine cistern is a space located on the ventral aspect of the pons. The cisterna magna is an opening on the subarachnoid space between the pia matter and the arachnoid.

The property described in the question is heterogeneity.Heterogeneity is when a single phenotype or genetic disorder can be caused by multiple numbers of genetic mutations.Other options:- Pleiotropy occurs when a single gene influences multiple phenotypic traits. The underlying mechanism is that the gene codes for a product that is used by various cells. A classic example of pleiotropy is the human disease PKU (phenylketonuria).- The penetrance of a disease-causing mutation is the proportion of individuals with the mutation who exhibit clinical symptoms. For example, the gene responsible for a particular autosomal dominant disorder has 70% penetrance, then 70% of those with the mutation will develop the disease, while 30% will not.

Atrial septal defects may also occur in association with a variety of other congenital heart defects, or in new-borns that are relatively small or premature. The following conditions are associated with an atrial septal defect:Ebstein’s anomalyFoetal alcohol syndromeHolt-Oram syndromeDown syndromeEllis van Creveld syndromeLutembacher’s syndrome Ostium primum defects occur frequently in individuals with Down syndrome or Ellis van-Creveld syndrome.Holt-Oram syndrome characterized by an autosomal dominant pattern of inheritance and deformities of the upper limbs (most often, absent or hypoplastic radii) has been attributed to a single gene defect in TBX5Fragile X syndrome is characterized by moderate intellectual disability in affected males and mild intellectual disability in affected females. The physical features in affected males are variable and may not be obvious until puberty. These symptoms can include a large head, long face, prominent forehead and chin, protruding ears, loose joints and large testes. Other symptoms can include flat feet, frequent ear infections, low muscle tone, a long narrow face, high arched palate, dental problems, crossed eyes (strabismus) and heart problems including mitral valve prolapse.

Craniopharyngiomas (also known as Rathke pouch tumours, adamantinomas or hypophyseal duct tumours) affect children mainly between the age of 5 and 10 years. It constitutes 9% of brain tumours affecting the paediatric population. These are slow-growing tumours which can also be cystic, and arise from the pituitary stalk, specifically the nests of epithelium derived from Rathke’s pouch. Histologically, this tumour shows nests of squamous epithelium which is lined on the outside by radially arranged cells. Calcium deposition is often seen with a papillary type of architecture.
ACTH-secreting pituitary adenomas are rare and mostly microadenomas. Paediatric astrocytoma’s usually occur in the posterior fossa. Although null cell adenomas can cause mass effect and give rise to the described symptoms, they are not suprasellar. Prolactinomas can also show symptoms of headache and disturbances in the visual field, however they are known to be small and slow-growing.

In the pattern of mendelian inheritance, X- linked dominant inheritance means that all who inherit the X chromosome will present with the condition. In the case of maternal x-linked inheritance sons and daughters have an equal chance of inheriting the condition as there is a 50% chance of inheriting the defective X chromosome from their mother as opposed to a non affected X chromosome from their father. However in paternal X-linked dominant inheritance, sons will be unaffected as they inherit a Y chromosome from their father while daughters are sure to inherit the defective X-chromosome.

Generally, bed-wetting before age 7 isn’t a concern as the child may still be developing night-time bladder control. The child is less than 5 years and most children will outgrow bed-wetting on their own. Therefore only reassurance and behavioural therapy are suggested at this stage.

Osteoid osteoma is a bone forming tumour which affects individuals in the second decade of life. The patient presents with a history of pain in the lower limbs which is mostly at night and responds to NSAIDS. If the pain doesn’t respond to NSAIDS, then other differentials should be considered.

Minimal-change disease (MCD) refers to a histopathologic glomerular lesion, typically found in children, that is almost always associated with nephrotic syndrome. The most noticeable symptom of MCD is oedema, which can develop very rapidly. Due to the renal loss of proteins muscle wasting and growth failure may be seen in children. Renal function is usually not affected and a proteinuria of more than 40 mg/h/m2 is the only abnormal finding in urinalysis.