The spinal muscular atrophies (SMAs) comprise a group of autosomal recessive disorders characterized by progressive weakness of the lower motor neurons. several types of spinal muscular atrophies have been described based on age when accompanying clinical features appear. The most common types are acute infantile (SMA type I, or Werdnig-Hoffman disease), chronic infantile (SMA type II), chronic juvenile (SMA type III or Kugelberg-Welander disease), and adult-onset (SMA type IV) forms.SMA type I – Acute infantile or Werdnig-Hoffman diseasePatients present before 6 months of age, with 95% of patients having signs and symptoms by 3 months. They have severe, progressive muscle weakness and flaccid or reduced muscle tone (hypotonia). Bulbar dysfunction includes poor suck ability, reduced swallowing, and respiratory failure. Patients have no involvement of the extraocular muscles, and facial weakness is often minimal or absent. They have no evidence of cerebral involvement, and infants appear alert.Reports of impaired fetal movements are observed in 30% of cases, and 60% of infants with SMA type I are floppy babies at birth. Prolonged cyanosis may be noted at delivery. In some instances, the disease can cause fulminant weakness in the first few days of life. Such severe weakness and early bulbar dysfunction are associated with short life expectancy, with a mean survival of 5.9 months. In 95% of cases, infants die from complications of the disease by 18 months.

According to the US immunisation schedule, the child is immunised. So this boy does not need any extra immunisation for tetanus now.

Aniridia is a genetic condition characterized by defects in the formation of a normal iris. The iris may be completely absent or only partially. One of the types of aniridia may be associated with other abnormalities like cataracts, glaucoma, corneal clouding, and nystagmus. The third type of aniridia is associated with intellectual disability, while a fourth type occurs in association with Wilm’s tumour. Aniridia may also be associated with amblyopia and buphthalmos, but macular hypoplasia is not a feature.

Due to breakdown of the red blood cell membrane in haemophilic patients, cholesterol crystals are formed by the lipids. On the other hand lipofuscin deposition does not occur in haemolysis or haemorrhage. Neutrophil accumulation suggests acute inflammation. Anthracotic pigment is an exogenous carbon pigment that deposits in the lung from dust. Russell bodies are intracellular accumulations of immunoglobins in plasma cells. Curschmann’s spirals and Charcot Leyden crystals are pathognomonic of asthma.

Bulimia nervosa is an eating disorder that involves frequent episodes of binge eating followed by inappropriate purging behaviour. The underlying reason for this behaviour is distorted self-image. Bulimia leads to several medical issues, including various laboratory derangements. Among these deranged laboratory parameters are the hormone cholecystokinin, which is found to be decreased in women having bulimia. It is hypothesized that the bingeing episodes observed in patients with bulimia are due to lower levels of CCK since normal levels of CCK are involved in maintaining satiety and controlling the urge to binge eat.

The first sign of pubarche in females is breast-bud development (thelarche).This begins between the ages of 9 and 12 years and continues to 12–18 years. Pubic hair growth occurs next (said to occur in stage 3), at ages 9–14 years, and is complete at 12–16 years. Menarche occurs relatively late in stage 4 (age 11–15 years) and is associated with a deceleration in growth. The peak height velocity is reached earlier (10–13 years) and growth is completed much earlier than in boys.

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

Advanced paternal age is associated with poor quality sperm leading to a reduction in overall fertility along with an increase in the occurrence of various medical disorders in the fetus. Advanced paternal age has been implicated as a risk factor for diseases like retinoblastoma, Marfan’s syndrome, neurofibromatosis, achondroplasia, autism spectrum disorders, schizophrenia, and acute lymphoblastic leukaemia. Down’s syndrome is mostly considered a consequence of advanced maternal age, but advanced paternal age has also been implicated as a risk factor. Turner syndrome is not found to be caused by advanced paternal age.

Any blood test used to detect HIV infection must have a high degree of sensitivity (the probability that the test will be positive if the patient is infected) and specificity (the probability that the test will be negative if the patient is uninfected). Unfortunately, no antibody test is ever 100 % sensitive and specific. Therefore, if available, all positive test results should be confirmed by retesting, preferably by a different test method. HIV antibody tests usually become positive within 3 months of the individual being infected with the virus (the window period). In some individuals, the test may not be positive until 6 months or longer (considered unusual). In some countries, home testing kits are available. These tests are not very reliable, and support such as pre and post test counselling is not available.

Intussusception is the most suggested case here based on the child’s symptoms. The urgent course of treatment is to bring the child to a paediatric surgical unit. If air reduction attempts fail, surgery will have to be done. Risk factors for intussusception include viral infection and intestinal lymphadenopathy.

The umbilical cord that connects the fetus to the placenta is about 50cm long. This tissue consists of the body stalk and vitelline duct. The former containing the allantoic diverticulum and the umbilical vessels. The latter contains the connection linking the digestive tube and the yolk sac. This cord is wrapped by stratum of ectoderm and gelatinous tissue or jelly of Wharton. The right umbilical vein plus the vitelline vessels and ducts disappear and this at birth the cord has three vessels which are the umbilical vein and two umbilical arteries.

The Chi squared test is used to find the relationship between two variables, determining whether they are not independent of each other. This test of statistical significance allows you to determine the degree of confidence with which you can accept or reject the null hypothesis. The student t test compares the significant differences in data means, while rank correlation, linear regression and the correlation coefficient all help to measure the linear relationship between variables.

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.

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.

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.

The cells in the testes that secrete testosterone are the Leydig cells.Other cells in testes include:- Spermatogonia: These are undifferentiated male germ cells which undergo spermatogenesis in the seminiferous tubules of the testes.- Sertoli cells: They are a part of the seminiferous tubule of the testes, cells are activated by FSH and nourish developing sperm cells.- Myoid: They are squamous contractile cells which generate peristaltic waves, they surround the basement membrane of testes.- Fibroblasts: Cells which synthesise collagen and the extracellular matrix.

Eczema herpeticum (also called Kaposi varicelliform eruption) is a disseminated viral illness usually associated with lymphadenopathy.It is most often caused by Herpes Simplex type 1 or type 2. Occasionally, other viruses such as coxsackievirus A16 may cause eczema herpeticum. Affected children usually develop itchy blisters and fever after coming in contact with an affected individual who may or may not display cold sores.It is characterised by an itchy and sometimes painful cluster of blisters most commonly on the face initially. This spreads over one to several weeks resulting in further crops of blisters which can become confluent. Lymphadenopathy and fever are common in these patients.The severity varies from mild illness to life-threatening, especially in immunocompromised children or young infants. It is markedly more common in children with atopic dermatitis. It is one of the few dermatological emergencies, and oral antivirals are often indicated. Referral to an ophthalmologist may be needed if there is eyelid or eye involvement. Occasionally, superadded skin infections caused by staphylococci and streptococci can occur.

After birth, the infant takes its first breath and is exposed to a myriad of stimuli. The pulmonary vessels dilate, and pulmonary vascular resistance (PVR) decreases remarkably while the systemic vascular pressure rises above the PVR. This allows blood from the right ventricle to enter the lungs for oxygenation. In most cases, this increased oxygenation, along with other factors, causes the ductal wall to constrict and the ductus arteriosus to close functionally. As left-sided pressures rise higher than right-sided pressures, the foramen ovale functionally closes. With the clamping of the umbilical cord and the cessation of blood flow, pressures in the portal sinus decrease. This causes the muscle in the sinus wall near the ductus venosus to contract. The lumen of the duct becomes filled with connective tissue, and, in two months, the ductus venosus becomes a fibrous strand embedded in the wall of the liver, thus establishing adult circulation.

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.

Osteochondromas, or osteocartilaginous exostoses, are the most common benign bone tumours, and tend to appear near the ends of long bones. The overgrowth can occur in any bone where cartilage forms bone, and they are capped by cartilage. They are most common in people between the ages of 10-20 years old.

Hyposplenism is associated with thrombocytosis. Other features of hyposplenism are: – Howell-Jolly bodies and acanthocytosis, occurring secondary to haemolysis.- Pappenheimer bodies: These are granular deposits of iron found within the RBCs.- Lymphocytosis and monocytosis.Causes for hyposplenism include:- Congenital asplenia- Iatrogenic splenectomy: Following trauma or treatment for ITP, thalassemia or spherocytosis).- Autosplenectomy: Secondary to sickle cell anaemia, coeliac disease, dermatitis herpetiformis, essential thrombocythemia or splenic arterial thrombosis).

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.

The aetiology of macrocephaly is diverse.The most common cause is benign familial macrocephaly characterized by enlargement of the subarachnoid spaces and accounts for almost 50% of cases.Other causes are:- Enlargement of skull bones – Hyperostosis cranii – associated with disorders such as osteogenesis imperfecta, achondroplasia, and osteopetrosis- Secondary enlargement due to bone marrow expansion – as seen in thalassemia major- Increase in volume of cerebrospinal fluid- Hydrocephalus, Choroid plexus papilloma, Benign familial macrocephaly- Megalencephaly – Leukodystrophies – Canavan disease, Alexander disease, megalencephalic leukoencephalopathy with subcortical cysts- Lysosomal storage disorders – Tay-Sachs, mucopolysaccharidosis, gangliosidosis- Neurocutaneous disorders – Tuberous sclerosis, Sturge-weber syndrome, neurofibromatosis, Gorlin syndrome- Autism spectrum disorder- Other syndromes – Fragile X syndrome, Cowden syndrome, Sotos syndrome- Increased intracranial pressure (ICP)- CNS infections, Pseudotumor cerebriSubdural collections including hygromas- Mass lesions and an increase in the volume of bloodTumourIntraventricular haemorrhage, subdural hematoma, arteriovenous malformation

90% of patients with meconium ileus have cystic fibrosis (CF). Indeed, in 10 – 15% of cases of CF, the patient presents with meconium ileus.

Crossover trials are characterized by the switching of study participants throughout the treatment groups, keeping a random order of switching. This randomization is important to determine any carry-over effect of different treatment modalities. The benefit of this study is the evaluation of the efficacy of various short-term treatment options for the relief of chronic conditions. The washout period is small in this type of study. Crossover studies are more efficient than the parallel studies, but they should be used according to the treatment options and outcomes.

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.

Acoustic neuroma/vestibular schwannoma is a benign slow-growing tumour. The clinical picture of the child suggests neurofibromatosis type 1 (NF1), with cafe-au-lait spots and axillary and inguinal freckling.

A lucid interval, in which the patient portrays a temporary improvement in condition after a traumatic brain injury, is especially indicative of an epidural haematoma.

The Chi-squared test would have been a useful test to compare the proportions in the scenario. However, due to the small sample size, Fisher’s exact test can be applied to analyse the significance of the difference. Adequate information is not given to determine what sample sizes were used to test the efficacy of the treatment, and to tell whether the treatment should be discontinued without further analysis on the data.

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