The most likely diagnosis is hypertrophic obstructive cardiomyopathy which is suggestive by the history, positive family history and ECG findings. Two-dimensional echocardiography is diagnostic for hypertrophic cardiomyopathy. In general, a summary of echocardiography findings includes abnormal systolic anterior leaflet motion of the mitral valve, LV hypertrophy, left atrial enlargement, small ventricular chamber size, septal hypertrophy with septal-to-free wall ratio greater than 1.4:1, mitral valve prolapse and mitral regurgitation, decreased midaortic flow, and partial systolic closure of the aortic valve in midsystole.

In mild-to-moderate heroin overdoses, arterial blood gas (ABG) analysis reveals respiratory acidosis. In more severe overdoses, tissue hypoxia is common, leading to mixed respiratory and metabolic acidosis.

The normal range for PaCO2 is 35-45 mmHg (4.67 to 5.99 kPa). Respiratory acidosis can be acute or chronic. In acute respiratory acidosis, the PaCO2 is elevated above the upper limit of the reference range (i.e., >45 mm Hg) with an accompanying academia (i.e., pH < 7.35). In chronic respiratory acidosis, the PaCO2 is elevated above the upper limit of the reference range, with a normal or near-normal pH secondary to renal compensation and an elevated serum bicarbonate levels (i.e., >30 mEq/L).

Arterial blood gases with pH = 7.31; pCO2 = 7.4 kPa; pO2 = 8.1 kPa would indicate respiratory acidosis.

Pneumocystis Jiroveci. This causative organism is responsible for pneumonia in individuals that have a compromised immune system. Symptoms include cyanosis, dry cough and in some cases, diffuse bilateral alveolar shadows on CXR. Co-trimoxazole is normally the treatment for this.

Liddle’s Syndrome is an autosomal dominant disorder that presents with hypertension usually in young patients, that do not respond to anti-hypertensive therapy and is later associated with hypokalaemia, low renin plasma, and low aldosterone levels as well. The other conditions listed do not present with hypertension and associated hypokalaemia.

Autonomic Neuropathy may involve the cardiovascular, gastrointestinal, genitourinary systems and the sweat glands.
Patients with generalized autonomic neuropathies may report ataxia, gait instability, or near syncope/syncope. In addition, autonomic neuropathies have further symptoms that relate to the anatomic site of nerve damage—gastrointestinal, cardiovascular, bladder, or sudomotor.
– Gastrointestinal autonomic neuropathy may produce the following symptoms:
Dysphagia, abdominal pain, nausea/vomiting, malabsorption, faecal incontinence, diarrhoea, constipation.
– Cardiovascular autonomic neuropathy may produce the following symptoms :
Persistent sinus tachycardia, orthostatic hypotension, sinus arrhythmia, decreased heart variability in response to deep breathing, near syncope upon changing positions from recumbent to standing.
– Bladder neuropathy (which must be differentiated from prostate or spine disorders) may produce the following symptoms:
Poor urinary stream
Feeling of incomplete bladder emptying
Straining to void
– Sudomotor neuropathy may produce the following symptoms:
Heat intolerance
Heavy sweating of head, neck, and trunk with anhidrosis of lower trunk and extremities
Gustatory sweating

Indications for surgery for the treatment of primary hyperparathyroidism:
1. Symptoms of hypercalcaemia such as thirst, frequent or excessive urination, or constipation
2. End-organ disease (renal stones, fragility fractures or osteoporosis)
3. An albumin-adjusted serum calcium level of 2.85 mmol/litre or above.

This patient presents with the classic triad of renal carcinoma: haematuria, loin pain and a mass in the kidneys. Management will entail right radical nephrectomy because of the 8x8cm solid mass and a left partial nephrectomy of the 3x3cm solid mass.

Memantine is an antagonist of the NMDA (N-Methyl-D-Aspartate)-receptor subtype of glutamate receptor. It is used to slow the neurotoxicity thought to be involved in Alzheimer’s disease and other neurodegenerative diseases.

Drug interactions:
When given concomitantly with other NMDA-receptor antagonists (e.g., ketamine, amantadine) increase the risk of psychosis.
Dopamine agonists, L-dopa, and anticholinergics enhance effects of memantine.
Antispasmodics (e.g., baclofen)  enhance effects, as memantine has some antispasmodic effects.
Drugs excreted by cationic transporters in the kidney (e.g. quinine, cimetidine, ranitidine) reduce excretion.

Common adverse effects include dizziness, headache, confusion, diarrhoea, and constipation.

Narcolepsy is a rare condition characterised by excessive daytime sleepiness, sleep paralysis, hypnagogic hallucinations, and cataplexy (sudden collapse triggered by emotion such as laughing or crying). There is no cure for narcolepsy. Treatment options include stimulants, such as methylphenidate (Ritalin) or modafinil (Provigil), antidepressants, such as fluoxetine (Prozac), citalopram (Celexa), paroxetine (Paxil), sertraline (Zoloft) and sodium oxybate (Xyrem). Modafinil has replaced methylphenidate and amphetamine as the first-line treatment of excessive daytime sleepiness (EDS).

Uhthoff’s phenomenon is worsening of vision following a rise in body temperature.
Lhermitte’s sign describes paraesthesia in the limbs on neck flexion.
Oppenheim’s sign is seen when scratching of the inner side of leg leads to extension of the toes. It is a sign of cerebral irritation and is not related to multiple sclerosis.
Werdnig-Hoffman’s disease is also known as spinal muscular atrophy.

Sitagliptin-induced pancreatitis can occur at any time after the initiation of therapy, even after several years. Patients taking sitagliptin who present with signs and symptoms of mild or severe pancreatitis should immediately discontinue sitagliptin and use an alternate medication regimen for control of type 2 diabetes.
In response to pancreatitis reported in post-marketing surveillance through the Adverse Event Reporting System (AERS), the FDA has issued revised prescribing information for sitagliptin stating that cases of acute pancreatitis have been reported with use, to monitor closely for signs and symptoms of pancreatitis, and to use sitagliptin with caution in patients with a history of pancreatitis.

Raloxifene is a selective oestrogen-receptor modulator (SERM) that has been approved for use in the prevention and treatment of osteoporosis in postmenopausal women.
A SERM interacts with oestrogen receptors, functioning as an agonist in some tissues and an antagonist in other tissues. Because of their unique pharmacologic properties, these agents can achieve the desired effects of oestrogen without the possible stimulatory effects on the breasts or uterus.

Carbon monoxide (CO) poisoning:
It is considered as the great imitator of other diseases as the patients present with a myriad of symptoms. The carbon monoxide diffuses rapidly across the pulmonary capillary membrane binding to the haem molecule with a very high affinity (240 times that of oxygen) forming carboxy-haemoglobin (COHb). Non-smokers have a baseline COHb of ,3% while smokers have a baseline COHb of 10-15%.

Clinical features of carbon monoxide toxicity:
Headache: 90% of cases (most common clinical feature)
Nausea and vomiting: 50%
Vertigo: 50%
Confusion: 30%
Subjective weakness: 20%
Severe toxicity: ‘pink’ skin and mucosa, hyperpyrexia, arrhythmias, extrapyramidal features, coma, death
Cherry red skin is a sign of severe toxicity and is usually a post-mortem finding.
Management
• 100% oxygen
• Hyperbaric oxygen therapy (HBOT)

The use of Hyperbaric oxygen therapy (HBOT) for treatment mild to moderate CO poisoning is not routine.
The selection criteria for HBOT in cases of CO poisoning include:
• COHb levels > 20-25%
• COHb levels > 20% in pregnant patient
• Loss of consciousness
• Severe metabolic acidosis (pH <7.1)
• Evidence of end-organ ischemia (e.g., ECG changes, chest pain, or altered mental status)

Haemophilia is a X-linked recessive disorder. In X-linked recessive inheritance only males are affected. An exception to this seen in examinations are patients with Turner’s syndrome, who are affected due to only having one X chromosome. X-linked recessive disorders are transmitted by heterozygote females (carriers) and male-to-male transmission is not seen. Affected males can only have unaffected sons and carrier daughters.

There are five prognostic factors which indicate poor prognosis in HOCM:
-family history of HOCM-related sudden cardiac death
-unexplained recent syncope
-large left ventricular wall thickness (MLVWT ≥ 30 mm)
-multiple bursts of nsVT on ambulatory electrocardiography
-hypotensive or attenuated blood pressure response to exercise

Diabetes insipidus (DI) is defined as the passage of large volumes (>3 L/24 hr) of dilute urine (< 300 mOsm/kg). It has the following 2 major forms:
Central (neurogenic, pituitary, or neurohypophyseal) DI, characterized by decreased secretion of antidiuretic hormone (ADH; also referred to as arginine vasopressin [AVP])
Nephrogenic DI, characterized by decreased ability to concentrate urine because of resistance to ADH action in the kidney.
The boy most probably has nephrogenic diabetes insidious (DI) not central DI so he is not responding to the ADH treatment.

Night sweats are a B symptom in Hodgkin lymphoma (HL) and imply a poor prognosis.

HL is a malignant proliferation of lymphocytes characterised by the presence of distinctive giant cells known as Reed-Sternberg cells. It has a bimodal age distribution being most common in the third and seventh decades of life.

Staging of HL is done according to the Ann Arbor staging system:

Stage
I: Single lymph node region (I) or one extra lymphatic site (IE)

II: Two or more lymph node regions on same side of the diaphragm (II) or local extra lymphatic extension plus one or more lymph node regions on same side of the diaphragm (IIE)

III: Lymph node regions on both sides of the diaphragm (III) which may be accompanied by local extra lymphatic extension (IIIE)

IV: Diffuse involvement of one or more extra lymphatic organs or sites

Suffix
A: No B symptoms

B: Presence of at least one of the following: unexplained weight loss >10% baseline during 6 months before staging; recurrent unexplained fever >38°C; recurrent night sweats—poor prognosis.

Polycythaemia vera (PV) is associated with a low ESR.

PV, also known as polycythaemia rubra vera, is a myeloproliferative disorder caused by clonal proliferation of marrow stem cells leading to an increase in red cell volume, often accompanied by overproduction of neutrophils and platelets. It has peak incidence in the sixth decade of life, with typical features including hyperviscosity, pruritus, splenomegaly, haemorrhage (secondary to abnormal platelet function), and plethoric appearance. PV is associated with a low ESR.

Some management options of PV include lose-dose aspirin, venesection (first-line treatment), hydroxyurea (slightly increased risk of secondary leukaemia), and radioactive phosphorus (P-32) therapy.

In PV, thrombotic events are a significant cause of morbidity and mortality. 5–15% of the cases progress to myelofibrosis or acute myeloid leukaemia (AML). The risk of having AML is increased with chemotherapy treatment.

The patient has primary Hypogonadism.
Since he already had two children, Klinefelter syndrome is excluded and the patient does not need karyotyping.
His lab results are normal indicating normal pituitary gland functions.
So the next step is testicular ultrasound as testicular tumour, infiltration or idiopathic failure is suspected.

Refeeding syndrome can be defined as the potentially fatal shifts in fluids and electrolytes that may occur in malnourished patients receiving artificial refeeding (whether enterally or parenterally). These shifts result from hormonal and metabolic changes and may cause serious clinical complications. The hallmark biochemical feature of refeeding syndrome is hypophosphatemia. However, the syndrome is complex and may also feature abnormal sodium and fluid balance; changes in glucose, protein, and fat metabolism; thiamine deficiency; hypokalaemia; and hypomagnesaemia.

Favus is a fungal infection of the scalp, resulting in the formation of a yellowish crusted plaque over the scalp and leads to scar formation with alopecia. Tinea capitus is a fungal infection of the scalp resulting in scaling and non scarring hair loss. Folliculitis presents with multiple perifollicular papules which can be caused by both bacteria and fungi. Cradle cap usually affects infants where the whole scalp is involved. It can lead to hair loss and responds to topical antifungals and keratolytics.

Androgen insensitivity syndrome (AIS), previously referred to as testicular feminization, is an X-linked disorder in which the patients are genotypically male (possessing and X and Y chromosome) and phenotypically female. This disorder is rare, with reported incidences from 1 in 20,000 to 1 in 60,000 live male births, and is the result of a missing gene on the X chromosome that is responsible for the cytoplasmic or nuclear testosterone receptor. In its absence, the gonad, which is a testis, produces normal amounts of testosterone; however, the end tissues are unable to respond due to the deficient receptors leading to the external genitalia developing in a female fashion. Anti-mullerian hormone, which is produced by the testis, is normal in these patients, leading to regression of the Mullerian duct. Wolffian duct development, which depends on testosterone, does not occur as the ducts lack the receptors.
The cumulative effect is a genotypic male with normal external female genitalia (without pubic or axillary hair), no menses, normal breast development, short or absent vagina, no internal sex organs, and the presence of testis. Frequently, these patients have bilateral inguinal hernias in childhood, and their presence should arouse suspicion of the diagnosis.

Melanocytic nevi are benign neoplasms or hamartomas composed of melanocytes. Melanocytes are derived from the neural crest and migrate during embryogenesis to selected ectodermal sites (primarily the skin and the CNS), but also to the eyes and the ears.
They tend to appear during early childhood and during the first 30 years of life. They may change slowly, becoming raised, changing color or gradually fading.. Pregnancy can increase the number of naevi as well as the degree of hyperpigmentation.
They may become malignant and this should be suspected if the naevus increases in size, develops an irregular surface or becomes darker, itches or bleeds.

This girl most probably has Turner’s syndrome, which is caused by the absence of one set of genes from the short arm of one X chromosome.
Turner syndrome is a lifelong condition and needs lifelong oestrogen replacement therapy. Oestrogen is usually started at age 12-15 years. Treatment can be started with continuous low-dose oestrogens. These can be cycled in a 3-weeks on, 1-week off regimen after 6-18 months; progestin can be added later.

In childhood, growth hormone therapy is standard to prevent short stature as an adult.

Fetal ovarian development seems to be normal in Turner syndrome, with degeneration occurring in most cases around the time of birth so pulsatile GnRH and luteinising hormone would be of no use.

Risk factors specific to depression:
-Family history of mental disorder.
-History of previous suicide attempts (this includes self-harm).
-Severe depression.
-Anxiety.
-Feelings of hopelessness.
-Personality disorder.
-Alcohol abuse and/or drug abuse.
-Male gender.

Protective Factors for Suicide.
Protective factors buffer individuals from suicidal thoughts and behaviour. To date, protective factors have not been studied as extensively or rigorously as risk factors. Identifying and understanding protective factors are, however, equally as important as researching risk factors.

Protective Factors:
-Effective clinical care for mental, physical, and substance abuse disorders
-Easy access to a variety of clinical interventions and support for help seeking
-Family and community support (connectedness)
-Support from ongoing medical and mental health care relationships
-Skills in problem solving, conflict resolution, and nonviolent ways of handling disputes
-Cultural and religious beliefs that discourage suicide and support instincts for self-preservation

Sildenafil administration to patients who are using organic nitrates, either regularly and/or intermittently, in any form is contraindicated.
Organic nitrates and nitric oxide (NO) donors exert their therapeutic effects on blood pressure and vascular smooth muscle by the same mechanism as endogenous NO via increasing cGMP concentrations.

Normal pressure hydrocephalus is a form of communicating hydrocephalus characterised by enlarged ventricles with normal opening pressure on lumbar puncture. For diagnostic purposes, a triad of urinary incontinence, gait abnormality and dementia is necessary. It is necessary to diagnose the condition early because it is reversible by placing a ventriculoperitoneal shunt. It is most common in patients aged more than 60 years.

Class I indications (i.e., the benefit greatly outweighs the risk, and the treatment should be administered): -Structural heart disease, sustained VT
-Syncope of undetermined origin, inducible VT or VF at electrophysiologic study (EPS)
-Left ventricular ejection fraction (LVEF) ≤35% due to prior MI, at least 40 days post-MI, NYHA class II or III
-LVEF ≤35%, NYHA class II or III
-LVEF ≤30% due to prior MI, at least 40 days post-MI
-LVEF ≤40% due to prior MI, inducible VT or VF at EPS

Class IIa indications (i.e., the benefit outweighs the risk and it is reasonable to administer the treatment):
-Unexplained syncope, significant LV dysfunction, nonischaemic cardiomyopathy
-Sustained VT, normal or near-normal ventricular function
-Hypertrophic cardiomyopathy with 1 or more major risk factors
-Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) with 1 or more risk factors for sudden cardiac death (SCD)
-Long QT syndrome, syncope or VT while receiving beta-blockers
-Nonhospitalized patients awaiting heart transplant
-Brugada syndrome, syncope or VT
-Catecholaminergic polymorphic VT, syncope or VT while receiving beta-blockers
-Cardiac sarcoidosis, giant cell myocarditis, or Chagas disease

Pseudomembranous colitis is caused by a C. difficile infection that causes membranes to form on the colon wall. It is caused most commonly by broad-spectrum antibiotics. This would include cephalosporins, broad-spectrum penicillin, and clindamycin. Macrolides and quinolones have also been reported as potential aetiologies, but much less commonly.

The best next step is to try a dairy-free diet, many patients may develop this in their lifetime. IBS is a diagnosis of exclusion, and one would need to rule lactose intolerance out as a potential aetiology first. She is only 28, and without overt bleeding or signs/sxs/labs suggestive of obstruction or inflammation; colonoscopy, flex sig and a barium enema are not indicated.