Brachymorphism-Onychodysplasia-Dysphalangism Syndrome

At a glance

Presumed genetic disorder causing short stature, hand abnormalities, and no or only mild intellectual impairment.

Synonym

BOD Syndrome.

Incidence

Approximately 14 cases have been reported in the literature.

Genetic inheritance

The exact mode of inheritance is unclear, but is postulated to be autosomal dominant but most cases appear to be sporadic. Although the syndrome has features in common with ☞Coffin-Siris Syndrome, it is supposed to be distinguishable by a generally milder phenotype and less severe intellectual impairment. However, some experts consider BOD to be a milder variant of Coffin-Siris Syndrome.

Diagnosis

Based on the clinical findings. To date, there are no molecular genetic tests available to confirm this disorder.

Clinical aspects

Intelligence is either normal or mildly to moderately reduced. Features include intrauterine, proportionate growth retardation and postnatal dwarfism. Typically, the fifth digits of the hands are hypoplastic with the middle phalanges shortened and the distal phalanx hypo- or aplastic. The proximal and distal phalanges of the fifth toes may be fused, and similar to the changes in the hands, hypo- or aplastic (middle and) distal phalanges of the fifth toes. The changes can be quite variable and asymmetric though and not infrequently have an increasing gradient from digits II to V. Most commonly, the osseous digital lesions are associated with hypo- or aplastic and dystrophic fingernails (onychodystrophy). Affected individuals have mild facial dysmorphism which may include micro- and/or brachycephaly, sparse hair, high forehead, flat malar area, strabismus, broad nasal tip with prominent nares, long philtrum, prominent lips, a wide mouth, and a pointed chin. Radiologic findings include aplasia, hypoplasia, or fusion of the fifth digit or toe and brachymesophalangism. One of the affected individuals had a cystic adenomatoid malformation of the lungs, two had an atrial septal defect (ASD; one had a secundum type ASD and the other one had a large primum ASD and mitral valve cleft requiring surgery), and one had a ventricular septal defect with patent ductus arteriosus, however, these findings do not appear to be a consistent feature of the syndrome. Life expectancy is normal.

Precautions before anesthesia

Routine preoperative assessment. Check for difficult airway management, but the facial dysmorphism is not expected to be severe enough to cause difficult airway management. Check for heart murmur and request an echocardiogram if a cardiac defect is suspected. Developmental delay may cause agitation and stress in the perioperative period; thus, anxiolytic and sedative premedication and/or presence of a parent (or primary caregiver) for induction of anesthesia may be beneficial.

Anesthetic considerations

Careful intraoperative positioning and padding is needed to avoid pressure sores. Venous access may be challenging due to ...