Errors of morphogenesis: concepts and terms. Recommendations of an international working group.

We describe a family in which lentigines were present in the index patient, in three of her seven siblings, in their mother, and in a niece (the daughter of an affected sister). Cutaneous myxomas were present in the index patient, in two of her brothers, and probably in their mother. In addition, the index patient had two cardiac myxomas, multiple myxoid mammary fibroadenomas, and the Cushing syndrome, and an affected brother had acromegaly caused by a growth hormone-secreting tumor of the pituitary gland. Thus, at least one manifestation of the complex of myxomas, spotty pigmentation, and endocrine overactivity has occurred in three successive generations of this family. Both male and female family members were affected, and 5 of the 11 children of affected persons had the disorder. The karyotypes of two affected persons were normal. These observations are consistent with mendelian dominant inheritance of the syndrome.

https://www.mayoclinicproceedings.org/article/S0025-6196(12)61843-6/pdf

Dominant Inheritance of the Complex of Myxomas, Spotty Pigmentation, and Endocrine Overactivity

Objective: To investigate the variable clinical picture of Mobius syndrome (MIM no. 157900) and to further understand the pathogenesis of the disorder. Methods: A standardized questionnaire was submitted to 37 Dutch patients with Mobius syndrome. All underwent standardized neurologic examination with special attention to cranial nerve functions, motor skills, and facial and limb anomalies. Results: Of 37 patients with facial paresis, 97% had bilateral and 3% had unilateral ocular abduction weakness. Further analysis showed isolated abducens nerve palsy in 9%, a conjugated horizontal gaze paresis in 48%, features of Duane retraction syndrome in 34%, and congenital fibrosis of the extraocular muscles in 9%. Other signs included lingual involvement (77%), dysfunction of palate and pharynx (56%), general motor disability (88%), poor coordination (83%), and respiratory abnormalities (19%). Conclusion: Mobius syndrome is more than a cranial nerve or nuclear developmental disorder. It is a syndrome of rhombencephalic maldevelopment involving predominantly motor nuclei and axons, as well as traversing long tracts. The authors also noted gaze palsies, Duane retraction syndrome, feeding and respiratory problems, and poor motor development, suggesting a regional developmental disorder.

Möbius syndrome redefined A syndrome of rhombencephalic maldevelopment

The frequency of various anomalies was compared in probands with Fanconi anaemia and their affected sibs. As probands are usually ascertained because of a 'characteristic' array of physical anomalies, the frequencies of these specific anomalies may be overestimated in probands, whereas their affected sibs may provide a more accurate estimate. The frequencies of growth retardation, skin hyperpigmentation, radial ray deformities, radial ray reduction deformities, hypogenitalia, and supernumerary thumbs were significantly lower in the affected sibs of probands than in probands. Since 25% of the affected sibs had no dysmorphic features, absence of dysmorphism is not sufficient to rule out the diagnosis.

/pdf/spectrum-of-anomalies-in-fanconi-anaemia-q0k3z2yhwo.pdf

Spectrum of anomalies in Fanconi anaemia.

The purpose of this study was to analyse the development of the axial skeleton in human trisomy 13 fetuses and to define which fields in the axial skeleton are affected in this condition. We investigated nine human fetuses with trisomy 13 and gestational ages of 14-19 weeks. Whole body radiographs and radiographs of midsagittal tissue blocks of the cranial base and the spine were studied. In the youngest fetus, 14 w GA, no malformations were observed. In eight fetuses, 17-19 weeks GA, malformations occurred in the lumbosacral spine. In four fetuses additional malformations were observed in the thoracic spine. The study showed that there was a correspondence between the extent of malformation in the lumbosacral spine and the thoracic spine. When mild malformation occurred in the lumbosacral region, no malformation was observed in the thoracic region, whereas malformation was observed in the thoracic region when there was extensive malformation in the lumbosacral region. Malformations did not occur in the cervical spine or the basilar part of the occipital bone, but the postsphenoidal part of the sphenoid bone was small and irregular in the six cases where it could be examined. In seven fetuses there was malformation or agenesis of the nasal bone. This pattern of axial skeletal malformations in trisomy 13 fetuses was not described previously. Comparisons are made with previous studies of the fetal axial skeleton in trisomy 18 and trisomy 21, where the pattern of malformations was different. We reiterate our recommendation that axial skeletal radiography should be part of the postmortem examination of fetuses with suspected or verified chromosome abnormalities.

Pattern of malformations in the axial skeleton in human triploid fetuses

Man’s experience of congenital malformations antedates recorded history and can be inferred from philology and the most ancient of legends. Indeed, the presence of Down syndrome in the chimpanzee (McClure et al., 1969, 1970) and of various X-linked disorders in other mammals (Ohno, 1967) means that even during phylogeny man lived side by side with mammalian cousins affected with homologous forms of his own genetic aberrations. The history of teratology has been written many times and is astoundingly voluminous (Gruber, 1964). It shows that the accomplishments of the early workers in the field consisted primarily of anatomical and clinical descriptions.

Sharon C. Colacino

Papers

Terminological, Diagnostic, Nosological, and Anatomical-Developmental Aspects of Developmental Defects in Man