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.

Based on the clinical scenario provided, the most probable diagnosis for this patient would be tuberous sclerosis which is an autosomal dominant condition.Among the options provided, only Neurofibromatosis Type 1 is inherited by an autosomal dominant pattern. Other options:- Beckwith-Wiedemann syndrome is an example of an imprinting disorder and results from abnormalities of inheritance or methylation of chromosome 11p15.- Cystic fibrosis is an autosomal recessive condition.- Duchenne Muscular Dystrophy is an example of an X-linked recessive condition.- Hypophosphataemic (Vitamin D resistant) rickets is an X-linked dominant condition.

HLA-DR (3 and 4) have been associated with an increased risk for idiopathic diabetes mellitus.Type 1 diabetes has a high heritability compared to type 2Identical twins have a 30-50% risk if their twin has type 1 diabetes

Haemolytic Uremic Syndrome affects children and is characterised by abdominal pain, a purpuric rash over the body, generalized pallor, haematuria and bloody diarrhoea. There is always a history of preceding diarrhoea caused usually by E.coli and it affects the renal system causing haematuria and deranged renal function tests.

Answer: RicketsRickets is a disease of growing bone that is unique to children and adolescents. It is caused by a failure of osteoid to calcify in a growing person. The signs and symptoms of rickets can include:pain – the bones affected by rickets can be sore and painful, so the child may be reluctant to walk or may tire easily| the child’s walk may look different (waddling)skeletal deformities – thickening of the ankles, wrists and knees, bowed legs, soft skull bones and, rarely, bending of the spinedental problems – including weak tooth enamel, delay in teeth coming through and increased risk of cavitiespoor growth and development – if the skeleton doesn’t grow and develop properly, the child will be shorter than averagefragile bones – in severe cases, the bones become weaker and more prone to fractures.Marfan syndrome (MFS) is a genetic disorder of the connective tissue. The degree to which people are affected varies. People with Marfan tend to be tall and thin, with long arms, legs, fingers and toes. They also typically have flexible joints and scoliosis. The most serious complications involve the heart and aorta, with an increased risk of mitral valve prolapse and aortic aneurysm. Other commonly affected areas include the lungs, eyes, bones and the covering of the spinal cord.Ehlers-Danlos syndrome is a group of inherited disorders that affect your connective tissues — primarily your skin, joints and blood vessel walls. People who have Ehlers-Danlos syndrome usually have overly flexible joints and stretchy, fragile skin. This can become a problem if you have a wound that requires stitches, because the skin often isn’t strong enough to hold them.A more severe form of the disorder, called Ehlers-Danlos syndrome, vascular type, can cause the walls of your blood vessels, intestines or uterus to rupture. Osteoporosis is a disease in which bone weakening increases the risk of a broken bone. It is the most common reason for a broken bone among the elderly. Bones that commonly break include the vertebrae in the spine, the bones of the forearm, and the hip. Until a broken bone occurs there are typically no symptoms. Bones may weaken to such a degree that a break may occur with minor stress or spontaneously. Chronic pain and a decreased ability to carry out normal activities may occur following a broken bone.Osteoporosis may be due to lower-than-normal maximum bone mass and greater-than-normal bone loss. Bone loss increases after menopause due to lower levels of oestrogen. Osteoporosis may also occur due to a number of diseases or treatments, including alcoholism, anorexia, hyperthyroidism, kidney disease, and surgical removal of the ovaries.

Metformin works by improving the sensitivity of peripheral tissues to insulin, which results in a reduction of circulating insulin levels. Metformin inhibits hepatic gluconeogenesis and it also increases the glucose uptake by peripheral tissues and reduces fatty acid oxidation. Metformin has a positive effect on the endothelium and adipose tissue independent of its action on insulin and glucose levels.Metformin was the first insulin sensitising drug (ISD) to be used in PCOS to investigate the role of insulin resistance in the pathogenesis of the syndrome Several effects have been reported as related to metformin in PCOS patients including restoring ovulation, reducing weight, reducing circulating androgen levels, reducing the risk of miscarriage and reducing the risk of gestational diabetes mellitus (GDM). Other studies have reported that the addition of metformin to the ovarian stimulation regime in invitro fertilization (IVF) improves the pregnancy outcome. These effects will be addressed individually.

Based on the presentation, the patient is probably a case of Crohn’s disease. The first-line treatment of Crohn’s disease is exclusive enteral nutrition.Exclusive enteral nutrition (EEN)This involves drinking a protein-based formula exclusively for 6–8 weeks. It has been shown to have superior mucosal healing when compared with steroids. Furthermore, it is nutritionally advantageous when compared to steroids and does not have the side-effect profile of steroids.Other options:- Intravenous steroids: This is the first-line treatment for ulcerative colitis (UC) or Crohn’s disease if there is rectal disease (which is not the case here). Side-effects include adrenal suppression, behavioural effects, osteopenia and changes in adipose tissue distribution.- Oral steroids: This can be used if EEN is not possible. However, the side-effect profile is less favourable and is not as effective concerning mucosal healing.- Parental nutrition and surgery: They may be occasionally required in severe cases that have failed first-line therapy.

Hyposplenism usually occurs after the surgical removal of the spleen or in pathological processes where the splenic tissue is replaced with abnormal tissue. It is often associated with diseases such as sickle cell disease, Coeliac disease, SLE and Dermatitis Herpetiformis. Myxoedema however bears no known association with hyposplenism. Patients with hyposplenism are at risk of fulminant bacterial infection.

Three physical changes – breast budding, pubic hair growth, and axillary hair growth in the order mentioned precede menarche. These changes are due to oestrogen, a hormone essential for pubertal development.The various pubertal changes in males include:-Testicular growth: It is the first sign of puberty occurring at around 12 years of age (Range = 10 – 15 years).- Testicular volume: An increase in the volume of testicles to 4 ml indicates the onset of pubertyThe various pubertal changes in females include:- The first sign is breast development at around 11.5 years of age (range = 9-13 years)- Followed by the onset of height spurt reaching the maximum in puberty (at 12 years of age)- The final change that occurs is termed menarche at 13 (11-15) years of age.Some of the other pubertal changes include:- Gynecomastia may develop in boys- Asymmetrical breast growth may occur in girls- Diffuse enlargement of the thyroid gland

Meconium aspiration syndrome (MAS) refers to breathing problems that a new-born baby may have when: – There are no other causes, and- The baby has passed meconium (stool) into the amniotic fluid during labour or deliveryThe most recent guidelines are as follows:- If the baby is vigorous (defined as having a normal respiratory effort and normal muscle tone), the baby may stay with the mother to receive the initial steps of new-born care. A bulb syringe can be used to gently clear secretions from the nose and mouth.- If the baby is not vigorous (defined as having a depressed respiratory effort or poor muscle tone), place the baby on a radiant warmer, clear the secretions with a bulb syringe, and proceed with the normal steps of new-born resuscitation (i.e., warming, repositioning the head, drying, and stimulating). If, after these initial steps are taken, the baby is still not breathing or the heart rate is below 100 beats per minute (bpm), administer positive pressure ventilation.Resuscitation should follow the same principles for infants with meconium-stained fluid as for those with clear fluidContinued care in the neonatal intensive care unit (NICU):Maintain an optimal thermal environment to minimize oxygen consumption.Minimal handling is essential because these infants are easily agitated. Agitation can increase pulmonary hypertension and right-to-left shunting, leading to additional hypoxia and acidosis. Sedation may be necessary to reduce agitation.An umbilical artery catheter should be inserted to monitor blood pH and blood gases without agitating the infant.Continue respiratory care includes oxygen therapy via hood or positive pressure, and it is crucial in maintaining adequate arterial oxygenation. Mechanical ventilation is required by approximately 30% of infants with MAS. Make concerted efforts to minimize the mean airway pressure and to use as short an inspiratory time as possible. Oxygen saturations should be maintained at 90-95%.Surfactant therapy is commonly used to replace displaced or inactivated surfactant and as a detergent to remove meconium. Although surfactant use does not appear to affect mortality rates, it may reduce the severity of disease, progression to extracorporeal membrane oxygenation (ECMO) utilization, and decrease the length of hospital stay.

47,XYY syndrome is characterized by an extra copy of the Y chromosome in each of a male’s cells. Although many males with this condition are taller than average, the chromosomal change sometimes causes no unusual physical features. Most males with 47,XYY syndrome have normal production of the male sex hormone testosterone and normal sexual development, and they are usually able to father children.47,XYY syndrome is associated with an increased risk of learning disabilities and delayed development of speech and language skills. Affected boys can have delayed development of motor skills or hypotonia.Other signs and symptoms of this condition include hand tremors or other involuntary movements (motor tics), seizures, and asthma. Males with 47,XYY syndrome have an increased risk of behavioural, social, and emotional difficulties compared with their unaffected peers. These problems include attention-deficit/hyperactivity disorder (ADHD)| depression| anxiety| and autism spectrum disorder.Physical features related to 47,XYY syndrome can include increased belly fat, macrocephaly, macrodontia, flat feet (pes planus), fifth fingers that curve inward (clinodactyly), widely spaced eyes (ocular hypertelorism), and scoliosis. These characteristics vary widely among affected boys and men.

Erythema Migrans is associated with Lyme disease, a tic transmitted infection caused by the spirochete Borrelia Burgdorferi. The rash usually appears at the bite site after 7 to 10 days. It is flat or slightly raised and migrates as the name suggests. Streptococcal throat infection and Crohn’s disease are both associated with erythema nodosum.Herpes simplex and Rheumatic fever may present with Erythema Multiforme and Erythema Marginatum respectively.

Klinefelter’s syndrome is the most common sex chromosome linked disorder with a karyotype of 47XXY. The incidence of the disease is 1 in 500-1000 male births. Childhood presentation consists of unusual growth spurt along with learning difficulties and delayed speech. The adolescence is marked by abnormal sexual maturation leading to hypogonadism and sub-fertility in adulthood.

Hyperkalaemia presents with high voltage (peaked) T waves on ECG. Other features on ECG include smaller p-waves and wider QRS complexes.

Bleeding oesophageal varices secondary to portal hypertension can cause a massive gastrointestinal haemorrhage resulting in shock. Perforated ulcer is less likely in this age group. Mallory Weiss tear would not likely result in a massive haemorrhage. Aorto-intestinal fistula is more common in older patients with abdominal aneurysms. Boerhaave’s syndrome is a result of a ruptured oesophagus following excessive vomiting.

As this boy was dry for a considerable period, there is a high chance of a secondary cause for the bed wetting, such as bladder infections, constipation, diabetes, psychological stress and hormonal problems etc. These have to be excluded.

The T wave represents ventricular repolarization. Other options:- P wave:Depolarization that spreads from the SA node throughout the atria. The wave lasts 0.08 to 0.1 seconds (80-100 ms).The isoelectric period after the P wave represents the time in which the impulse is travelling within the AV node.- P-R interval:Time from the onset of the P wave to the beginning of the QRS complex. The wave ranges from 0.12 to 0.20 seconds in duration.Represents the time between the onset of atrial depolarization and the onset of ventricular depolarization- QRS complex:It represents ventricular depolarization. The duration of the QRS complex is normally 0.06 to 0.1 seconds.- ST-segment:The isoelectric period following the QRS. It represents the period in which the entire ventricle is depolarized and roughly corresponds to the plateau phase of the ventricular action potential- U wave: It is a small positive wave which may follow the T wave. It represents the last remnants of ventricular repolarization.- Q-T intervalIt represents the time for both ventricular depolarization and repolarization to occur, and therefore roughly estimates the duration of an average ventricular action potential.The interval ranges from 0.2 to 0.4 seconds depending upon heart rate.At high heart rates, ventricular action potentials shorten in duration, which decreases the Q-T interval. Therefore the Q-T interval is expressed as a corrected Q-T (QTc) by taking the Q-T interval and dividing it by the square root of the R-R interval (interval between ventricular depolarizations). This allows an assessment of the Q-T interval that is independent of heart rate.The normal corrected Q-Tc interval is less than 0.44 seconds.

Infectious mastitis and breast abscesses are predominantly caused by bacteria that colonize the skin. S. aureus is the most common causative agent, followed by coagulase-negative Staphylococci. The majority of S. aureus isolated are now methicillin-resistant S. aureus (MRSA)Some breast infections (and up to 40% of breast abscesses) may be polymicrobial, with the isolation of aerobes (Staphylococcus, Streptococcus, Enterobacteriaceae, Corynebacterium, Escherichia coli, and Pseudomonas) as well as anaerobes (Peptostreptococcus, Propionibacterium, Bacteroides, Lactobacillus, Eubacterium, Clostridium, Fusobacterium, and Veillonella). A study of primary and recurrent breast abscesses showed that smokers were more likely to have anaerobes recovered (isolated in 15% of patients).Unusual breast infections may be the initial presentation of HIV infection. Typhoid is a well-recognized cause of breast abscesses in countries where this disease is prevalent.

Oligohydramnios is a deficiency in the amniotic fluid volume, measured via ultrasound. Maternal factors associated with oligohydramnios include conditions where there is placental insufficiency such as chronic hypertension, preeclampsia or a thrombotic disorder, post-term pregnancy, premature rupture of membranes, certain chromosomal abnormalities, and obstructions of the foetal urinary tract. On the other hand conditions that are associated with polyhydramnios (excess amniotic fluid) include maternal diabetes, multiple gestations, Rh incompatibility and pulmonary abnormalities.

The most likely organism is enterohemorrhagic verotoxin-producing E.coli. It usually causes haemolytic uremic syndrome.

Crohn’s disease rarely manifests in an acute manner.

Polio and giardiasis usually manifest with non-bloody diarrhoea.

Thread worms don’t always cause symptoms, but people often experience itchiness around their bottom or vagina. It can be worse at night and disturb sleep.

Alport syndrome is a genetic condition characterized by kidney disease, hearing loss, and eye abnormalities. Alport syndrome can have different inheritance patterns. About 80 percent of cases are caused by mutations in type IV collagen genes (COL4A5) and are inherited in an X-linked autosomal recessive pattern, although other inheritance patterns exist. Alport syndrome has autosomal dominant inheritance in about 5 percent of cases.

People with Alport syndrome experience progressive loss of kidney function. Almost all affected individuals have blood in their urine (haematuria), which indicates abnormal functioning of the kidneys. Many people with Alport syndrome also develop high levels of protein in their urine (proteinuria). The kidneys become less able to function as this condition progresses, resulting in end-stage renal disease (ESRD).

People with Alport syndrome frequently develop sensorineural hearing loss, which is caused by abnormalities of the inner ear, during late childhood or early adolescence. Affected individuals may also have misshapen lenses in the eyes (anterior lenticonus) and abnormal coloration of the light-sensitive tissue at the back of the eye (retina). These eye abnormalities seldom lead to vision loss.

Significant hearing loss, eye abnormalities, and progressive kidney disease are more common in males with Alport syndrome than in affected females.

The azygos lobe is usually well seen on the chest radiograph, where it is limited by the azygos fissure, a fine, convex (relative to the mediastinum) line that crosses the apex of the right lung.

Milestones of 6 monthsSocial and EmotionalKnows familiar faces and begins to know if someone is a stranger Likes to play with others, especially parents Responds to other people’s emotions and often seems happy Likes to look at self in a mirror Language/CommunicationResponds to sounds by making sounds Strings vowels together when babbling (“ah,” “eh,” “oh”) and likes taking turns with the parent while making sounds Responds to own name Makes sounds to show joy and displeasure Begins to say consonant sounds (jabbering with “m,” “b”) Cognitive (learning, thinking, problem-solving)Looks around at things nearby Brings things to mouth Shows curiosity about things and tries to get things that are out of reach Begins to pass things from one hand to the other Movement/Physical DevelopmentRolls over in both directions (front to back, back to front) Begins to sit without support When standing, supports weight on legs and might bounce Rocks back and forth, sometimes crawling backwards before moving forward

Relative risk is the probability of an outcome occurring in an exposed group as compared to the probability of that outcome in an unexposed group. In the scenario given, 50% of the children exposed developed the disease while only 10% of the children who were unexposed developed the disease. The relative risk was therefore 50/10=5. There is no further information about whether the study was controlled, the confidence interval, or the type of study. It therefore cannot be confirmed whether the chemical is causative and if it should be avoided.

The anti-B antibodies in a patient with blood group A belong to the IgM class of immunoglobulins.Note:IgM is the largest antibody formed of 5 antibodies attached together. This functions to agglutinate or clump antigens. The associated anti-A and anti-B antibodies are usually IgM produced in the first years of life by sensitisation to environmental substances such as food, bacteria, and viruses.Other options:- IgG is the most common antibody. It is a single antibody complex.- IgD is found on the surface of B-lymphocytes.- IgE is bound to tissue cells, especially mast cells and eosinophils.

Time and EventWeek 1: ImplantationWeek 2: Formation of bilaminar diskWeek 3: Formation of primitive streakFormation of notochordGastrulationWeek 4: Limb buds begin to formNeural tube closesHeart begins to beatWeek 10: Genitals are differentiated

Familial/inherited short stature is the most likely and commonest factor resulting in short stature among the children. Klinefelter syndrome is characterised by tall stature, widely spaces nipples and infertility. Other factors include congenital heart disease, maternal deprivation and diabetes mellitus but these are the rare causes.

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 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.

This clinical presentation is highly suggestive of choking. According to the BLS algorithm, the next step in managing a case of choking in a conscious child with an ineffective cough is five back blows.Other options:- Adrenaline intramuscularly: The history is similar to anaphylaxis, but the absence of a rash or oedema and the acute onset make choking more likely in this situation. Thus, adrenaline will not be of use in this patient.- CPR at a ratio of 15:2: Since the child is conscious, it is not advised. If the child were unconscious, you would commence basic life support.- Five abdominal thrusts: In the given scenario, the child is an infant. Abdominal thrusts are avoided in infants due to the risk of intra-abdominal injury.