The “3-Minute MRCPCH Practice”

CORRECT ANSWER:

In an unresponsive patient, reduced consciousness leads to a loss of tone in the pharyngeal muscles and the soft palate. This allows the tongue to fall back and occlude the oropharynx, creating a partial upper airway obstruction.

The vibration of these relaxed tissues during respiration produces the characteristic sound of snoring. The head tilt and chin lift manoeuvre is the first-line intervention which works by physically lifting the hyoid bone and tongue base away from the posterior pharyngeal wall, thereby relieving the obstruction and resolving the snoring. This is the most frequent cause of airway compromise in unconscious patients.

WRONG ANSWER ANALYSIS:

Option A (Spasm of the vocal cords) is incorrect as laryngospasm would typically present with a high-pitched inspiratory stridor, not snoring.

Option B (Swelling of the tongue from anaphylaxis) is less likely as angio-oedema would not be expected to resolve completely and immediately with only a chin lift manoeuvre.

Option C (Accumulation of copious secretions) would produce a gurgling sound, and while airway manoeuvres help, clearance would typically require suctioning.

Option E (Compression of the trachea from an external mass) would cause stridor and is a fixed obstruction that would not be relieved by altering the position of the tongue and soft palate.

CORRECT ANSWER:

C because of the strong and well-established genetic association between Type 1 Diabetes Mellitus (T1DM) and coeliac disease.

Both are autoimmune conditions linked by shared genetic susceptibility, primarily through the HLA class II genes. Specifically, the HLA-DQ2 haplotype is present in approximately 90% of individuals with coeliac disease and is also very common in those with T1DM. The HLA-DQ8 haplotype is another important shared genetic risk factor.

This shared genetic predisposition explains the significantly increased prevalence of coeliac disease in children with T1DM, estimated to be between 4-10%. National guidelines, including those from NICE, recommend regular screening for coeliac disease in all children with T1DM due to this high co-occurrence, often at diagnosis and then periodically, especially if symptoms like poor growth, abdominal pain, or unexplained anaemia develop.

Option A (HLA-B27) is incorrect as it is primarily associated with seronegative spondyloarthropathies, such as ankylosing spondylitis and juvenile idiopathic arthritis.

Option B (HLA-DR4) is incorrect because while it is strongly associated with T1DM, HLA-DQ2 is the most significant shared haplotype predisposing to both conditions.

Option D (HLA-Cw6) is incorrect as its strongest association is with psoriasis, particularly early-onset Type 1 psoriasis.

Option E (HLA-B51) is incorrect because it is the main genetic susceptibility factor for Behçet's disease.

CORRECT ANSWER:

Horseshoe kidney is the most common structural renal anomaly found in individuals with Turner syndrome, occurring in approximately 15% of cases. This fusion anomaly, typically at the lower poles, results from abnormal migration of the nephrogenic cells.

While often asymptomatic, it can predispose individuals to urinary stasis, infection, stone formation, and, rarely, hydronephrosis. For this reason, national guidelines recommend that all girls diagnosed with Turner syndrome undergo a baseline renal ultrasound at the time of diagnosis to screen for this and other less common collecting system anomalies. This surveillance allows for early detection and management of potential urological complications, which is a key aspect of the multidisciplinary care required for these patients.

WRONG ANSWER ANALYSIS:

Option A (Renal agenesis) is incorrect as it is a much rarer finding in Turner syndrome compared to horseshoe kidney.

Option B (Autosomal dominant polycystic kidney disease) is incorrect because it is a distinct genetic disorder with its own inheritance pattern and is not a recognised association with Turner syndrome.

Option D (Duplex kidney) is incorrect because although it is a recognised collecting system anomaly in Turner syndrome, it is significantly less prevalent than a horseshoe kidney.

Option E (Vesicoureteric reflux) is incorrect as it describes a functional issue of the ureterovesical junction rather than a primary structural anomaly of the kidney itself, and it is not the most common anomaly.