CF is inherited in an autosomal recessive manner.This means that to have CF, a person must have a mutation in both copies of the CFTR gene in each cell. People with CF inherit one mutated copy of the gene from each parent, who is referred to as a carrier.CF carriers can pass their copy of the CFTR gene mutation to their children. Each time two CF carriers have a child together, the chances are: 25 percent (1 in 4) the child will have CF50 percent (1 in 2) the child will be a carrier but will not have CF25 percent (1 in 4) the child will not be a carrier of the gene and will not have CFThis male’s parents are obligate carrier because he has a sibling with CFSo the chances he is a carrier too are 2 in 3The risk of having an affected child is the chance of both himself and his partner being carriers: (2/3 x 1/25 = 2/75) x 1/4 = 1/150.

Clotrimazole interferes with the ergosterol biosynthesis by decreasing ergosteron I biosynthesis, increasing membrane permeability, and disrupting membrane-bound enzyme systems.Vaginal candidiasis is an extremely common condition. Predisposing factors include:- diabetes mellitus- drugs: antibiotics, steroids- pregnancy- immunosuppression – iatrogenic

As this boy has experienced significant dry spells in the past, it is unlikely that a structural abnormality is causing the enuresis. The only therapies that have been shown to be effective in randomized trials are alarm therapy and treatment with desmopressin acetate or imipramine. Bladder training exercises are not recommended. Desmopressin acetate is the preferred medication for treating children with enuresis.

The commonest time for bacterial meningitis is in the 1st month of life and group B Streptococcus is the commonest organism. The anterior fontanelle is full, but does not bulge with normal flexion. Neurological manifestations include seizures, irritability, poor tone, lethargy and tremors, however no findings of sensorineural deafness have been noted. One of the risk factors for introduction of meningeal infection is Meningomyelocele.

The most probable diagnosis for this patient would be external angular dermoid.External angular dermoids typically form where there are overlapping tissue planes such as the midline. They contain a caseous material. The cysts are essentially benign in nature and are excised for cosmetic purposes or when they encroach on vision.Other options:- Branchial remnant typically presents as a supraclavicular pit.- Sebaceous cysts tend to be present on the scalp.- There is nothing in the clinical scenario to suggest a vascular malformation such as pigment change or ‘bag of worms’.- Lymphatic malformations are typically found in the neck or under the axilla.

The parotid duct (Stensen’s duct), which provides an exit for the gland’s secretions, passes through the anterior edge of the gland in the superficial lobe, turns medially at the anterior border of the masseter, penetrates the buccinator, then enters the oral cavity lateral to the second maxillary molar.

The external aspect of the tympanic membrane is lined by stratified squamous epithelium. Clinical correlation: Following middle ear infections, this type of epithelium can migrate into the middle ear through a perforated tympanic membrane.The ear is composed of three anatomically distinct regions: – External ear: Auricle is composed of elastic cartilage covered by skin. The lobule has no cartilage and contains fat and fibrous tissue. External auditory meatus is variable in length, measuring approximately 2.5cm long in fully grown children. Lateral third of the external auditory meatus is cartilaginous, and the medial two-thirds is bony. The greater auricular nerve innervates the region. The auriculotemporal branch of the trigeminal nerve supplies most of the external auditory meatus and the lateral surface of the auricle. – Middle ear: It is the space between the tympanic membrane and cochlea. The aditus leads to the mastoid air cells is the route through which middle ear infections may cause mastoiditis. Anteriorly the eustachian tube connects the middle ear to the nasopharynx. The tympanic membrane consists of an outer layer of stratified squamous epithelium, a middle layer of fibrous tissue and an inner layer of mucous membrane continuous with the middle ear. The chorda tympani nerve passes on the medial side of the pars flaccida. The glossopharyngeal nerve and pain innervate the middle ear. Thus, pain may radiate to the middle ear following tonsillectomy. – Ossicles:Malleus attaches to the tympanic membrane (the Umbo). Malleus articulates with the incus (synovial joint). Incus attaches to stapes (another synovial joint). – Internal ear:It consists of the cochlea, semicircular canals, and vestibule. Organ of Corti is the sense organ of hearing and is located on the inside of the cochlear duct on the basilar membrane. Vestibule accommodates the utricle and the saccule. These structures contain endolymph and are surrounded by perilymph within the vestibule. The semicircular canals lie at various angles to the petrous temporal bone. All share a common opening into the vestibule.

The endocardial cushions in the heart are the mesenchymal tissue that make up the part of the atrioventricular valves, atrial septum and ventricular septum. An incomplete fusion of these mesenchymal cells can cause an atrioventricular septal defect. The terms endocardial cushion defect, atrioventricular septal defect and common atrioventricular canal defect can be used interchangeably with one another.

Correlation is a bivariate analysis that measures the strength of association between two variables and the direction of the relationship.Pearson r correlation: Pearson r correlation is the most widely used correlation statistic to measure the degree of the relationship between linearly related variables. Pearson’s correlation coefficient is the test that measures the statistical relationship, or association, between two continuous variables. It is known as the best method of measuring the association between variables of interest because it is based on the method of covariance. It gives information about the magnitude of the association, or correlation, as well as the direction of the relationship.The non-parametric Spearman or Kendall rank correlation coefficient is used if neither variable has a normal distribution or the sample size is small (i.e. <20).

Mongolian spots are, hyper-pigmented, non-blanching patches present on the back and gluteal region at birth. They are commonly found in African and Asian ethnic groups, and can also present in infants of Mediterranean and middle eastern descent. Though the spots usually disappear by puberty, some may persist into adulthood.

ABC : Airway, breathing, circulation is the order of assessment in any patient that is unconscious and apnoeic.

The autosomal dominant pattern of inheritance involves the presence of at least one of the defected copies of the gene in an individual to develop a specific diseased condition. Examples of this mode of inheritance include myotonic dystrophy, neurofibromatosis, achondroplasia, etc. Still’s disease, also called juvenile idiopathic arthritis, is not a heritable disease. Tay-Sachs disease is an autosomal recessive disease., while spinocerebellar ataxia and Friedreich’s ataxia are caused by trinucleotide repeat expansion.

McBurney’s point is found 2/3rds of the way along an imaginary line that runs from the umbilicus to the anterior superior iliac spine on the right-hand side. On examination, features of generalised peritonitis can be observed if the appendix has perforated.Retrocecal appendicitis may have relatively fewer signs.Digital rectal examination may reveal boggy sensation if a pelvic abscess is present.Diagnosis is typically based on raised inflammatory markers coupled with compatible history, and examination findings.Ultrasound is useful in females where pelvic organ pathology can be a close differential diagnosis. Although it is not always possible to visualise the appendix on ultrasound, the presence of free fluid (always pathological in males) should raise suspicion. Ultrasound examination can also show evidence of luminal obstruction and thickening of the appendix.Management: Definitive management of appendicitis and appendicular perforation is appendicectomy which can be performed via either an open or laparoscopic approach.Simultaneous administration of metronidazole reduces wound infection rates. Patients with perforated appendicitis require copious abdominal lavage. Patients without peritonitis who have an appendix mass should receive broad-spectrum antibiotics and consideration given to performing an interval appendicectomy.

The most probable diagnosis for this patient would be a duplex kidney with an ectopic ureter inserting below the bladder neck. Rationale: The Weigert-Myer law states that the upper moiety ureter inserts inferior and medial to the lower moiety ureter. Other options:- Horseshoe kidney would display as a single pelvic kidney on an ultrasound scan.- Ureterocele would be a cystic lesion within the bladder or may prolapse at birth. – Continence should not be affected by polycystic kidney disease. – The overactive bladder would cause frequency and urgency, neither of which is mentioned in the history.

Somogyi effect presents with night-time hypoglycaemia followed by early-morning hyperglycaemia, hence the glycosuria.

The gastrocolic reflex is a physiological reflex that involves increase in colonic motility in response to stretch in the stomach and by-products of digestion in the small intestine. It is shown to be uneven in its distribution throughout the colon, with the sigmoid colon affected more than the right side of the colon in terms of a phasic response. Various neuropeptides have been proposed as mediators of this reflex, such as serotonin, neurotensin, cholecystokinin and gastrin.

Alpha-fetoprotein has significance primarily as a tumour marker, but maternal levels are frequently measured to detect some of the congenital abnormalities, in which the levels of alpha-fetoprotein are either increased or decreased. The conditions associated with raised alpha-fetoprotein levels are: spina bifida, anencephaly, myelomeningocele, oesophageal atresia, congenital nephrotic syndrome, and turner’s syndrome. Down’s syndrome or trisomy 21 is associated with low levels of maternal alpha-fetoprotein.

In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Twenty-two of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males and females. Females have two copies of the X chromosome, while males have one X and one Y chromosome.

Liddle’s syndrome,  is an autosomal dominant disorder, that is characterized by early, and frequently severe, high blood pressure associated with low plasma renin activity, metabolic alkalosis, low blood potassium, and normal to low levels of aldosterone. Liddle syndrome involves abnormal kidney function, with excess reabsorption of sodium and loss of potassium from the renal tubule. Bartter Syndrome also presents with hypokalaemia, however blood pressure of these patients is usually low or normal.

This girl most likely has Turner syndrome (TS) also known as 45,X, a condition in which a female is partly or completely missing an X chromosome. Signs and symptoms vary among those affected. Often, a short and webbed neck, low-set ears, low hairline at the back of the neck, short stature, and swollen hands and feet are seen at birth. Typically, they are without menstrual periods, do not develop breasts, and are unable to have children. Heart defects, diabetes, and low thyroid hormone occur more frequently. Most people with TS have normal intelligence. Many, however, have troubles with spatial visualization such as that needed for mathematics. Vision and hearing problems occur more often. Turner syndrome is not usually inherited from a person’s parents. No environmental risks are known and the mother’s age does not play a role. As a chromosomal condition, there is no cure for Turner syndrome. However, much can be done to minimize the symptoms including prescribing growth hormone, either alone or with a low dose of androgen, and oestrogen replacement therapy which is crucial long term for maintaining good bone integrity, cardiovascular health and tissue health

Persistent pulmonary hypertension of the new-born is secondary to the failure of normal circulatory transition at birth, leading to an abnormally high pulmonary vascular resistance. This elevated resistance causes right-to-left shunting of blood and hypoxemia. It can be caused by parenchymal lung diseases (meconium aspiration syndrome, pneumonia or ARDS), lung hypoplasia (like occurring in oligohydramnios or diaphragmatic hernia), or it can be idiopathic. Other possible causes include maternal indomethacin use, group B streptococcal septicaemia, and high-pressure ventilation. Duct dependent congenital heart disease does not lead to persistent pulmonary hypertension.

Fitz-Hugh-Curtis syndrome (FHCS), or perihepatitis, is a chronic manifestation of pelvic inflammatory disease (PID). It is described as an inflammation of the liver capsule, without the involvement of the liver parenchyma, with adhesion formation accompanied by right upper quadrant pain. A final diagnosis can be made through laparoscopy or laparotomy via direct visualization of violin string-like adhesions or through hepatic capsular biopsy and culture. FHCS is a complication of PID. Microorganisms associated with PID are thought to spread in one of three ways:-Through spontaneous ascending infection, microbes from the cervix or vagina travel to the endometrium, through the fallopian tubes, and into the peritoneal cavity. Complications include endometritis, salpingitis, tubo-ovarian abscess, pelvic peritonitis, and perihepatitis.-Microbes can also spread via lymphatic channels such as an infection of the parametrium from an intrauterine device.-Finally, the hematogenous spread is also possible such as with tuberculosis.

Infective endocarditis (IE) is caused by a bacterial, or fungal infection which damages the heart’s endothelium and can thus lead to changes in heart function, valve incompetencies, possible cardiac failure, as well other associated skin and organ changes. Organisms common in IE include Staphylococcus aureus and Streptococcus viridians. The HACEK organisms (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella species) are common in neonates. The Duke criteria uses 2 major, or 1 major and 3 minor criteria, or 5 minor criteria to diagnose infective endocarditis. Major criteria include:- a positive blood culture and evidence of endocardial involvement. Minor criteria include: – evidence of predisposition (a heart condition of injection drug use)- a fever- vascular phenomena such as Janeway lesions- immunologic phenomena such as Osler’s nodes and Roth’s spots; and- microbiological or serological evidence of active infection.

Auscultatory findings of VSD vary with the size of the defect. Small VSDs typically produce murmurs ranging from a grade 1 to 2/6 high-pitched, short systolic murmur (due to tiny defects that actually close during late systole) to a grade 3 to 4/6 holosystolic murmur (with or without thrill) at the lower left sternal border; this murmur is usually audible within the first few days of life (see table Heart Murmur Intensity). The precordium is not hyperactive, and the 2nd heart sound (S2) is normally split and has normal intensity.Moderate to large VSDs produce a holosystolic murmur that is present by age 2 to 3 wk; S2 is usually narrowly split with an accentuated pulmonary component. An apical diastolic rumble (due to increased flow through the mitral valve) and findings of heart failure (e.g., tachypnoea, dyspnoea with feeding, failure to thrive, gallop, crackles, hepatomegaly) may be present. In moderate, high-flow VSDs, the murmur is often very loud and accompanied by a thrill (grade 4 or 5 murmur). With large defects allowing equalization of left ventricular and right ventricular pressures, the systolic murmur is often attenuated.

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.

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.

Benign neonatal sleep myoclonus is a condition characterised by neonatal onset myoclonic jerks during NREM. Characteristic for this disorder is the absence of electroencephalographic findings.

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.

Consuming iron in its Fe2+ (ferrous form) form can improve the ability to absorb dietary iron in patients with iron deficiency anaemia (IDA). Clinical features of IDA include:- Koilonychia- Atrophic glossitis- Post-cricoid webs- Angular stomatitisThe peripheral blood smear shows the following abnormal RBC morphologies:- Target cells- Pencil poikilocytes- Microcytic-hypochromic cells

It is recommended that a woman wait one month after stopping isotretinoin before trying to become pregnant. Usually, isotretinoin is no longer found in a woman’s blood 4-5 days after the last dose and most of its by-products should be gone within 10 days after the last dose.