A Concise Clinical Description of Bloom’s Syndrome

BSyn is a very rare medical entity that was described over half a century ago, in New York City in 1954 by dermatologist David Bloom. The most prominent and the only constant physical feature of BSyn is abnormally small size. A distinguishing feature of BSyn's smallness is the retention of normal body proportions, the exception being the head which usually is disproportionately small. Two additional features that help distinguish the person with BSyn from most other diminutive individuals are (i) a striking paucity of subcutaneous fat tissue throughout infancy and childhood, and (ii) a redness of the cheeks and nose that characteristically makes its appearance in infancy after sun exposure. Although the facial skin condition can be severe, blistering and cracking of the lower lip being particularly aggravating, in many with BSyn it is a minor matter; avoidance of direct sun exposure is salutary.

A girl of 3 with BSyn, sister of the young lady pictured on page 1. She was 79 cm. tall and had mild erythema of the nose, cheeks, and lip margins. Her adult height would be 127 cm.

In persons with BSyn, feeding problems are common during infancy for still unclear reasons. Typically the baby shows a less-than-normal interest in nursing, and later in eating. Gastro-esophageal reflux has been demonstrated in some (specifically in all of the few appropriately examined), and it is suspected to be common and greatly under-diagnosed. Unexplained bouts of diarrhea may result in life-threatening dehydration. Non-volitional feeding via a gastric tube has been employed in a few cases, and that does increase fat deposition but not linear growth.

Infections of two important types are commoner in BSyn than in others, of the middle ear and lung (pneumonia). At least some of these may be related to the gastro-esophageal reflux, presumably as result of repeated micro-aspirations. (This serious possibility requires further clinical investigation.) Possibly contributing to a tendency to upper respiratory tract infections, which also are increased in frequency in many of those with BSyn, is an immune deficiency, a feature of most of the affecteds.

Puberty is reached at the usual age. Women, many of whom have proven to be fertile, experience premature onset of the menopause. Affected men who have been appropriately studied have proven to be azospermic, or in one case severely oligospermic.

Two brothers of 17 and 19. The one on the left, who has BSyn, presents the characteristic facial erythema and proportional dwarfism, the two main features of the condition. The young man with BSyn is 147 cm tall, his unaffected brother 183 cm.
A child of 6 with BSyn, showing mild facial erythema. He was 89 cm. tall. His adult height would be 128 cm.
Although mental capacity appears adequate in most persons with BSyn, and although some have excelled in school and obtained higher academic degrees, more than expected exhibit a lack of interest in learning; a very few have been frankly mentally deficient. Throughout childhood and in adulthood, general physical ability is normal, many enjoying participation in sports. The exceptionally pleasant and optimistic personality of most persons with BSyn, seemingly the result of the proper support from parents and teachers who understand BSyn itself, permits a happy child- and adulthood for the vast majority of affected persons.

The premature onset of features usually associated with aging is not part of BSyn; however, an important health problem of BSyn is a greater-than-normal risk of developing any of three age-associated disorders, each a disorder that is common in the general population. These three, in the order of their increasing frequency in BSyn, are (i) chronic obstructive lung disease, usually including severe bronchiectasis; (ii) diabetes that resembles the standard adult-onset type and that, although usually mild, can be accompanied by the usual complications of diabetes itself; and, (iii) malignant neoplasia of a wide variety of anatomical sites and types. The last two appear to be different in BSyn only in their excessive frequency and in their arising at earlier-than-normal ages, therefore necessitating medical surveillance which will make possible prompt management if and when they arise.

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