From 1972 to 1979 34 patients with homozygous familial hypercholesterolaemia were seen in one clinic in Johannesburg. All were Afrikaners and most lived in Transvaal Province. Their epidemiological, genetic, clinical, and biochemical characteristics were studied. The course of the disease varied considerably among the 34 patients, with no fewer than six surviving into their fourth or fifth decades. In some patients arterial atheroma was severe while cutaneotendinous xanthomas were slight and vice versa. Coronary heart disease was common but peripheral and cerebral arterial disease was rare. Another prominent finding was high concentrations of low-density lipoprotein cholesterol coupled with low high-density lipoprotein cholesterol values. The prevalences of homozygotes and heterozygotes with familial hypercholesterolaemia in Transvaal Afrikaners, calculated from this group of patients, were 1 in 30 000 and 1 in 100 respectively. These figures are the highest ever reported and may help to explain why South African whites have the

Twenty-three patients with 24 carotid body tumours are reviewed. A high incidence of malignancy (30%) was encountered. It is recommended that all carotid body tumours be removed unless there are contraindicating medical or technical reasons.

The external branch of the superior laryngeal nerve (ELN) is intimately associated with the superior thyroid artery (STA) in relation to the superior pole of the thyroid gland, rendering it vulnerable to injury during the ligation of this vessel during thyroidectomy. Although most texts acknowledge the fact that the nerve is in close relation to the STA, there has not been an anatomical study to relate the position of the ELN to the superior pole of the thyroid gland. The aim of this study was to determine the shortest distance, from the most superior point of the thyroid gland, to the ELN. Bilateral micro-dissection on 43 adult cadavers, excluding those with thyroid pathology and previous thyroidectomies, was undertaken. The most superior point of the superior pole of the thyroid gland was identified and the shortest distance to the ELN was measured with a digital calliper (accuracy 0.01 mm). The metric study indicated a mean distance from the ELN to the superior pole of a normal sized thyroid gland of 5.76 mm (range: 2.00-11.26) on the right, and 6.17 mm (range: 2.78-13.48) on the left. From the literature, it is clear that the ELN may even be closer to the superior pole of an enlarged thyroid gland. The recommendation to stay on the substance of the superior pole of the thyroid gland when ligating the STA remains valid, as the nerve is extremely close in relation to the superior pole of the normal thyroid gland.

Doppler pulse recordings in a patient with asymptomatic popliteal entrapment were compared with those in 25 normal subjects. A drop in pulse amplitude and ankle systolic pressure produced by forcible leg extension and active foot plantar flexion distinguished the patient with the anomaly from the controls, in whom no change was noted during these manoeuvres. This simple, non-invasive test thus diagnosed a potentially limb-threatening congenital abnormality in an asymptomatic patient with equivocal arteriographic findings.

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