Cystinosis is a condition characterized by accumulation of the amino acid cystine (a building block of proteins) within cells. This condition is inherited in an autosomal recessive pattern.Excess cystine damages cells and often forms crystals that can build up and cause problems in many organs and tissues. The kidneys and eyes are especially vulnerable to damage| the muscles, thyroid, pancreas, and testes may also be affected.There are three distinct types of cystinosis. In order of decreasing severity, they are nephropathic cystinosis, intermediate cystinosis, and non-nephropathic or ocular cystinosis.Nephropathic cystinosis begins in infancy, causing poor growth and a particular type of kidney damage (renal Fanconi syndrome) in which certain molecules that should be reabsorbed into the bloodstream are instead eliminated in the urine. The kidney problems lead to the loss of important minerals, salts, fluids, and many other nutrients. The loss of nutrients impairs growth and may result in soft, bowed bones (hypophosphatemic rickets), especially in the legs. The nutrient imbalances in the body lead to increased urination, thirst, dehydration, and abnormally acidic blood (acidosis). By about the age of 2, cystine crystals may be present in the clear covering of the eye (cornea). The build-up of these crystals in the eye causes pain and an increased sensitivity to light (photophobia). Untreated children will experience complete kidney failure by about the age of 10. Other signs and symptoms that may occur in untreated people, especially after adolescence, include muscle deterioration, blindness, inability to swallow, diabetes, thyroid and nervous system problems, and an inability to father children (infertility) in affected men.The signs and symptoms of intermediate cystinosis are the same as nephropathic cystinosis, but they occur at a later age.

Burkitt lymphoma is associated with the c-myc gene translocation, usually t(8|14). Burkitt lymphoma is a rare high-grade non-Hodgkin lymphoma endemic to west Africa and the mosquito belt. It has a close association with the contraction of Epstein-Barr virus (EBV). Burkitt lymphoma often presents with symmetrical painless lymphadenopathy, systemic B symptoms (fever, sweats, and weight loss), central nervous system involvement, and bone marrow infiltration. Classically in the textbooks, the patient also develops a large jaw tumour.Other aforementioned options are ruled out because:1. t(9|22)—Chronic myeloid leukaemia2. t(15|17)—Acute promyelocytic leukaemia3. t(14|18)—Follicular Lymphoma4. t(11|14)—Mantle Cell Lymphoma

Odds ratios are best described as the odds of an event in one group divided by the odds of the event in another. They form an alternative to the relative risk in case–control studies and are close to the relative risk when events are rare. The odds are the number of the event divided by the number without the event, which is less intuitive than the risk, which is the number with the event divided by the total. Odds ratios are therefore less intuitive than relative risks. Logistic regression analysis outputs variable coefficients which are the log of the odds ratio.

The type of significance test used depends on whether the data is parametric (can be measured, usually normally distributed) or non-parametric.
Parametric tests:
Student’s t-test – paired or unpaired*
Pearson’s product-moment coefficient – correlation

Non-parametric tests:
Mann-Whitney U test – unpaired data
Wilcoxon signed-rank test – compares two sets of observations on a single sample
chi-squared test – used to compare proportions or percentages
Spearman, Kendall rank – correlation.

The outcome measured is not normally distributed, i.e. it is non-parametric. This excludes the Student’s t-tests. We are not comparing percentages/proportions so the chi-squared test is excluded. The Mann–Whitney U test is a nonparametric test of the null hypothesis that it is equally likely that a randomly selected value from one sample will be less than or greater than a randomly selected value from a second sample.
This test can be used to investigate whether two independent samples were selected from populations having the same distribution.

Among the given options, psoriasis is not associated with hypertrichosis.The causes of hypertrichosis include:- Drugs: minoxidil, ciclosporin, and diazoxide.- Congenital hypertrichosis lanuginosa and congenital hypertrichosis terminalis.- Porphyria cutanea tarda- Anorexia nervosa

Intrauterine growth restriction refers to the failure of the fetus to grow in accordance with the weeks of gestation. There are two types of growth restriction, symmetrical and asymmetrical. Causes include various genetic abnormalities, fetal infections, maternal health conditions, etc. Risk factors for the development of IUGR include fetal echogenic bowel, maternal age above 40 years, low PAPP-A levels, maternal smoking or cocaine use, etc. Fetal echogenic bowel implies a brighter than usual fetal intestines on ultrasonography. It is a marker associated with trisomy 21, which is a cause of IUGR.

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.

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

Key Observations:

1. Cyanosis and Low Oxygen Saturation:
   • Central cyanosis indicates mixing of oxygenated and deoxygenated blood.
   • The aortic oxygen saturation is low (76%), indicating a significant amount of deoxygenated blood entering systemic circulation.
2. Pressure Analysis:
   • The right ventricle pressure is significantly elevated (110/6 mmHg), suggesting an obstructive lesion like pulmonary stenosis or an increased volume load due to a shunt.
   • The pulmonary artery pressure is low (20/5 mmHg) despite the high right ventricular pressure, suggesting an obstruction to flow from the right ventricle to the pulmonary artery, consistent with pulmonary stenosis.
3. Oxygen Saturation Analysis:
   • There is a notable drop in oxygen saturation from the left ventricle (87%) to the aorta (76%), indicating a mixture of oxygenated and deoxygenated blood in the systemic circulation, suggestive of a right-to-left shunt.

Differential Diagnosis:

1. Pulmonary Stenosis:
   • Supported by elevated right ventricular pressure and low pulmonary artery pressure.
2. Ventricular Septal Defect (VSD):
   • Would typically cause left-to-right shunting, leading to increased pulmonary blood flow and higher oxygen saturation in the right ventricle and pulmonary artery, which is not observed here.
3. Over-riding Aorta:
   • Seen in conditions like Tetralogy of Fallot where the aorta receives blood from both the right and left ventricles, leading to mixed oxygen saturation.
4. Right-to-Left Shunt:
   • The data indicates a right-to-left shunt, with low oxygen saturation in the aorta, suggesting that deoxygenated blood is bypassing the lungs and entering systemic circulation.
5. Aortic Stenosis:
   • Typically presents with high left ventricular pressure and a pressure gradient between the left ventricle and the aorta, which is not observed here.

Conclusion:

Given the data, the most likely abnormalities present in this patient are Pulmonary Stenosis, Right-to-Left Shunt, and Over-riding Aorta. These findings are consistent with a condition like Tetralogy of Fallot, where all these features are present.

Sepsis can be described as a condition in which there is a dysregulated inflammatory response to an infection. In the case of neonates, sepsis can be life threatening and may present with respiratory distress more than 4 hours after birth, shock, seizures, and multi organ failure. Risk factors that further point to sepsis include prolonged rupture of maternal membranes for more than 24 hours before birth, a history of a maternal fever during labour, or parenteral antibiotic treatment given to the mother for a suspected or confirmed bacterial infection.

Breastfeeding may be significantly impaired (up to 25%) by breast augmentation. Equally, breast engorgement, which occurs due to vascular congestion, reduces nipple protrusion and subsequent ability to breastfeed successfully. In the latter, regular feeding or expressing is required.

Compared to the rest of the options, Meckel’s diverticulum with ectopic gastric mucosa seems to be the most probable diagnosis, as it can lead to fresh bleeding.Fresh red bleeding can be caused by haemorrhoids, polyps or a massive GI bleed.

There are 6 pharyngeal arches, the fifth does not contribute any useful structures and often fuses with the sixth arch. The structures arising from the aortic arches are as follows:First aortic arch: It regresses except for a very small part that gives rise to the maxillary artery.Second aortic arch: It regresses except for a very small part giving rise to the stapedial artery.Third aortic arch: This arch is the source of the common carotid artery and the proximal part of the internal carotid artery, and the external carotid which arises as a bud from this arch.Right Fourth aortic arch: Is the genesis of the proximal part of the right subclavian artery.Left Fourth aortic arch: Gives rise to the medial portion of the arch of the aorta.Fifth aortic arch: The fifth aortic arch regresses completely and very early in the development.Sixth aortic arch: Either of the sixth aortic arches divides into ventral and dorsal segments, and therefore, their derivatives also divide into these two segments.Right Sixth Arch:Ventral: Gives rise to the right pulmonary artery.Dorsal: It degenerates completely and loses its connection with the dorsal aorta.Left Sixth ArchVentral: It gives rise to the left pulmonary artery that goes to the left pulmonary bud.Dorsal: It forms a vital connection during intrauterine life between the left pulmonary artery and the arch of the aorta. This structure is called ductus arteriosus.

The differentials of the child’s condition are likely to include an Iron deficiency anaemia, or a hemoglobinopathy such as sickle cell disease or thalassemia based on the presentation of pallor, growth failure and easy fatiguability. While the full blood count and film present a hypochromic microcytic anaemia with reticulocytosis, the normal serum ferritin levels rule out iron deficiency anaemia. Thalassemia is to be suspected over sickle cell disease as the patient comes from the Mediterranean region known for a high incidence of thalassemia. Sickle cell anaemia also tends to present with normocytic normochromic red blood cells, with many sickled cells. Vitamin B12 deficiency and Aplastic anaemia are ruled out as they present with a macrocytic anaemia, and a decrease in white blood cells, platelets and red blood cells respectively.

The main result of a correlation is called the correlation coefficient (or r). It ranges from -1.0 to +1.0. The closer r is to +1 or -1, the more closely the two variables are related.If r is close to 0, it means there is no relationship between the variables. If r is positive, it means that as one variable gets larger the other gets larger. If r is negative it means that as one gets larger, the other gets smaller (often called an inverse correlation).

Sepsis is a medical emergency that describes the body’s systemic immunological response to an infectious process that can lead to end-stage organ dysfunction and death. The fever, alongside the clinical presentation, make sepsis the likely diagnosis. A temperature >38 degrees in an infant <3months of age warrants investigation.

Precocious puberty is the attainment of normal pubertal biochemical and physical features at an abnormally early age. The age cut-offs commonly used to define precocious puberty are 8 years for females and 9 years for males. Precocious puberty may be central (true) or peripheral (false) based on the aetiology. Central precocious puberty is due to the premature activation of the hypothalamic-pituitary-gonadal axis, which in turn leads to the development of secondary sexual characteristics at an earlier than usual age. The best laboratory investigation to diagnose central precocious puberty is a gonadotropin-releasing hormone stimulation test, which is regarded as the gold standard. It requires the collection of multiple blood samples at different time points to measure FSH and LH levels. If the LH levels increase to >8IU/L after stimulation with GnRH, then the diagnosis of central precocious puberty is confirmed.

Klinefelter syndrome is a sex chromosome disorder in boys and men that results from the presence of an extra X chromosome in cells. People typically have 46 chromosomes in each cell, two of which are the sex chromosomes. Females have two X chromosomes (46,XX), and males have one X and one Y chromosome (46,XY). Most often, boys and men with Klinefelter syndrome have the usual X and Y chromosomes, plus one extra X chromosome, for a total of 47 chromosomes (47,XXY).Cri-du-chat (cat’s cry) syndrome, also known as 5p- (5p minus) syndrome, is a chromosomal condition that results when a piece of chromosome 5 is missing.Pierre Robin syndrome is not caused by a single gene defect but is a sequence.Meningomyelocele does not follow usual patterns of inheritance.

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.

Most healthy infants and children grow predictably, following a typical pattern of progression in weight, length, and head circumference. Normal human growth is pulsatile| periods of rapid growth (growth spurts) are separated by periods of no measurable growth Growth hormone levels and responsiveness’ develop in late infancy, increase during childhood and peak during puberty.Typical milestones — General guidelines regarding length or height gain during infancy and childhood include the following:- The average length at birth for a term infant is 20 inches (50 cm)- Infants grow 10 inches (25 cm) during the first year of life- Toddlers grow 4 inches (10 cm) between 12 and 24 months, 3 inches (7.5 cm) between 24 and 36 months, and 3 inches (7.5 cm) between 36 and 48 months- Children reach one-half of their adult height by 24 to 30 months- Children grow 2 inches per year (5 cm per year) between age four years and puberty- There is a normal deceleration of height velocity before the pubertal growth spurt.Growth continues past pubertal growth spurt as there is increase in spinal length.

Low oxygen delivery in hypotension, hypoxia, oedema, intracranial hypertension or changes in cerebral blood flow should all be prevented to avoid secondary brain injury. There is no evidence to suggest that hypothermia prevents secondary brain injuries.

Precocious puberty is the attainment of normal pubertal biochemical and physical features at an abnormally earlier age. The age cut-offs commonly used to define precocious puberty are 8 years for females and 9 years for males. The onset of normal puberty is triggered by gonadotropic-releasing hormones from the hypothalamus.In most of the familial cases, the condition is transmitted by affected father. In boys, this makes up about 5% of the cases.Full adult height potential is not achieved in patients of precious puberty, although there is an advanced bone maturation.

Teenagers may have poor eating habits and neglect to take their vitamin supplements. They are less likely than older women to be of adequate pre-pregnancy weight or to gain an adequate amount of weight during pregnancy. Low weight gain increases the risk of having a low birthweight baby. Weight gain is maximal during the 2nd trimester.aPTT and gallbladder emptying is decreased during pregnancy whereas d-dimers is increased.

The child has a history of pharyngitis followed 10 days later by signs of glomerulonephritis. In this particular case, it is most probably a post-streptococcus glomerulonephritis which accounts for 80% of paediatric cases of glomerulonephritis.

The IM dose of adrenaline for anaphylaxis in:< 6 months: 150 micrograms (0.15ml 1 in 1,000)6 months - 6 years: 150 micrograms (0.15ml 1 in 1,000)6 - 12 years: 300 micrograms (0.3ml 1 in 1,000)Adult and child > 12 years: 500 micrograms (0.5ml 1 in 1,000)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:- ABCD- Remove the allergen- IM adrenaline or Nebulised adrenaline- IV Hydrocortisone – pro re nata IV fluid support. – Followed by observation.

Vesicoureteric reflex (VUR) is described as the retrograde flow of urine from the bladder into the ureter due to an incompetent uterovesical junction. In primary VUR the lower urinary tract functions normally, while secondary VUR is associated with a poorly functioning lower urinary tract. The incidence of VUR is highest in new-born girls. They can present with hydronephrosis, or urinary tract infections.

Gilbert’s syndrome is an autosomal recessive condition that results from defective bilirubin conjugation due to a deficiency of UDP glucuronyl transferase – 1. The prevalence is approximately 1-2% in the general population.The clinical presentation of Gilbert’s syndrome include:- Unconjugated hyperbilinaemia- Jaundice can occur during an intercurrent illnessManagement:Blood investigations usually reveal a rise in bilirubin following prolonged fasting or intravenous nicotinic acid.No treatment required for these patients.Other options:- CYP2C9 deficiency causes reduced warfarin metabolism, and subsequent enhanced drug effects. – Pancreatic disease, cholestasis, excessive alcohol consumption and certain drugs are common causes of raised GGT levels- Defective hepatocyte excretion of conjugated bilirubin is related to the pathophysiology of Dubin-Johnson syndrome- Reduced CYP2C19 levels can lead to the disordered metabolism of clopidogrel and other drugs such as proton-pump inhibitors, anticonvulsants and sedatives.

Chickenpox is caused by the varicella-zoster virus. The clinical signs of infection are fever and a maculopapular rash – this is a unique rash with both flat and raised lesions on the skin.

Congenital LQTS arises from mutations in genes that code for ion channels within myocytes.These mutations all cause ventricular action potentials to be prolonged, resulting in a lengthened QT interval on ECG. The congenital long-QT syndrome (LQTS) is a life-threatening cardiac arrhythmia syndrome that represents a leading cause of sudden death in the young. LQTS is typically characterized by a prolongation of the QT interval on the ECG and by the occurrence of syncope or cardiac arrest, mainly precipitated by emotional or physical stress.LQTS type 1Most common type of congenital LQTSDefect: loss of function mutation on the KCNQ1 gene located on chromosome 11p → defective slow delayed rectifier voltage-gated potassium channelSubtypesJervell and Lange-Nielsen syndrome Associated with congenital deafnessAutosomal recessiveAssociated with ventricular tachyarrhythmiasRomano-Ward syndrome No associated deafnessAutosomal dominantAssociated with ventricular tachyarrhythmias

Polycythaemia is a condition in which there is an increased red cell mass and increasing blood viscosity, which decreases its ability to flow. It is not associated with food allergies, but is fundamentally caused by either an overproduction of red blood cells, or a reduction in the volume of plasma. Abdominal pain, constipation, loose and frequent stools, and pallor are all non IGE mediated symptoms of food allergy according to NICE guidelines in the UK.