Axial skeletogenesis in human autosomal aneuploidies: A radiographic study of 145 second trimester fetuses

Comprehensive phenotyping of fetuses with trisomy 18: a perinatal center experience

Trisomy 18 is the second most common aneuploidy after trisomy 21. It presents with varying degrees of heterogeneous clinical phenotypes involving multiple organ systems, with a high mortality rate. Clinical assessment of fetal trisomy 18 is always challenging. In this study, we describe the phenotypes of the fetuses with trisomy 18 from a perinatal cohort. We reviewed fetuses with trisomy 18 in referrals for perinatal autopsy over the period of 15 years. A detailed phenotyping of the fetuses with trisomy 18 was executed by perinatal autopsy. Appropriate fetal tissues were obtained to perform genomic testing. We observed trisomy 18 in 16 fetuses (2%) in our cohort of 784 fetal/neonatal losses and a perinatal autopsy was performed on all of them. Abnormal facial profile was the most frequent anomaly (10/16, 62%) followed by anomalies of the extremities (9/16, 56%), and cardiac defects (6/16, 37%). We also observed esophageal atresia, diaphragmatic hernia, and neural tube defect. The study represents one of the largest cohorts of trisomy 18 from a perinatal center from a developing country and highlights the clinical heterogeneity attributed to trisomy 18. We also report a recurrence of trisomy 18 in a family.

Ontogeny of morphological variations in the vertebral column: Prevalence and bony variability in young Spanish children

Pre- and postnatal development and variability in discrete vertebral traits have been poorly described in embryonic studies. Numerous authors have reported that these variations are observable only from adolescence; scientific publications on the vertebrae of fetuses and infants are scarce. Thus, the aims of this study were to (1) describe the ontogeny and variability of anatomical variations in the vertebral column of a Spanish infant population and (2) analyze the frequency and relationship between sex, age, and intertrait variables. A total of 4728 vertebrae from 197 skeletons were studied. The age at death ranged from 22 intrauterine weeks to 8 years. Twenty morphological traits related to vertebral column development were analyzed. A descriptive statistical analysis was performed, and the chi-square test was used to measure the relationship between sex, age, and intertrait variables. We observed that 88.32% of skeletons expressed discrete traits along the spine. In fetuses, the double transverse foramen and unclosed transverse process of the axis were the most prevalent traits. In infants older than one year, the appearance of the L5 cleft neural arch, unclosed transverse process of the atlas, and craniocaudal shifts were frequent. A significant result was found between sex and the unclosed transverse process in the axis. The intertrait relationship was significant for all traits that shared the same embryonic structure. Morphological variations became visible following the appearance of ossification centers during the pre- and postnatal periods, and their etiology was associated with embryonic development.

Cervical ribs in human early life: morphological variability and first identification as a morbidity criterion in a past population

Despite the medical literature on supernumerary cervical ribs in extant adult samples, little is known about their development and occurrence in early infancy. The documentation of cervical ribs in modern samples of fetuses and neonates is indeed affected by ethical as well as technical limitations. The aim of the present study was to investigate their frequencies and morphological variability in the first known archaeological collection of very young children with this anatomical variant. The study sample comes from the 8B-51 necropolis on the Saï island (Sudan) and dates to the Classic Kerma Period (XVIIIe-XVIe centuries BC). It consists of 64 individuals deceased between 24 weeks of amenorrhoea and 2 years of age. Bilateral or unilateral cervical ribs were found in 27 individuals. A total of 43 cervical ribs were identified, 38 of which are fully preserved. According to these observations, at least 42% of the individuals have unilateral or bilateral cervical ribs, with an average maximum length of < 1 cm. This frequency is very high compared to those observed in contemporary adult samples (up to 3%). First, the comparison of our results with biological and genetic research demonstrating the link between the occurrence of cervical ribs and a reduced chance of survival during infancy allows the first identification of this trait as an indicator of morbidity in an archaeological collection, a morbidity to which a genetic homogeneity or even endogamy could contribute. Second, the number of ribs studied makes it possible to propose a morphological classification based on the general shape and the shape of the articular facets, classification that can be used tos refine the analyses of the trait in future samples.

Cervical ribs and other abnormalities of the vertebral pattern in children with esophageal atresia and anorectal malformations

BACKGROUND

In mammals the vertebral column has a constant pattern, particularly in the cervical region, which is likely the result of stabilizing selection. The prevalence of cervical ribs and extended vertebral pattern abnormalities is increased in deceased fetuses and neonates and associated with structural and chromosomal anomalies. The hypothesized close interaction between vertebral patterning and organogenesis in early embryogenesis could be studied in children with esophageal atresia and anorectal malformations by evaluating the radiographs of the vertebral column and the type and number of associated anomalies METHODS: The vertebral pattern of 367 children diagnosed with an esophageal atresia (n = 135), anorectal malformation (n = 215), or both (n = 17) was assessed on radiographs.

RESULTS

The vertebral pattern was abnormal in 170/202 (84.2%) children in whom this could be assessed, and cervical ribs were present in 147/335 (43.9%). Extended vertebral pattern abnormalities became more frequent with an increasing number of associated structural abnormalities. Cervical ribs were particularly common in children with chromosomal and genetic abnormalities (18/20, 90.0%).

CONCLUSIONS

Cervical ribs are frequent and abnormal vertebral patterns are more extended in the presence of associated anomalies. These findings support the hypothesized selection against vertebral patterning variations and emphasize the relevance of assessment of the vertebral pattern.

Nonossified cervical vertebrae in Wolf-Hirschhorn Syndrome: A case report

RATIONALE

Wolf-Hirschhorn Syndrome (WHS) is a rare disorder caused by the loss of the distal part of the short arm of chromosome 4, and has various phenotypes depending on the deletion size. Although many articles report on urinary tract malformations or ophthalmologic abnormalities, there are few descriptions of the skeletal anomalies. This is an extremely rare case of cervical dysplasia in WHS.

PATIENT CONCERNS

A 24-year-old pregnant woman was transferred to our hospital at 21 gestational weeks for intrauterine growth retardation and oligohydramnios and decided to preserve the pregnancy after evaluation. A female was born at full term by normal vaginal delivery, weighing 1791 g. The patient was suspected to have congenital dysplasia of the cervical vertebrae on the routine newborn chest radiograph, and cervical spine magnetic resonance imaging revealed nonossification of the C3 and C4 vertebral bodies.

DIAGNOSIS

The newborn had the "Greek warrior helmet" face typical of WHS. A deletion was detected in the distal portion of the short arm of chromosome 4 (p 16.3) by fluorescence in situ hybridization analysis.

INTERVENTIONS

She was hospitalized for nutritional management and congenital anomaly evaluation for a month before being discharged with rehabilitation and antiepileptic drugs.

OUTCOMES

The patient has been readmitted with seizure attacks 5 times to date. At one year of age, she still shows severe head lag and feeding problems. Her last weight was below the 3rd centile.

LESSONS

Although cervical dysplasia is a rarely reported morphology in WHS, it may provide artefacts for diagnosing WHS as cervical anomalies, unlike facial anomalies or developmental delays, are seldom found in congenital disease.

Prenatal Incidence and Clinical Value of the Absence of 12th Ribs in a Population in a Setting of Detailed Second-Trimester Sonography

OBJECTIVES

We aimed to determine the incidence of the absence of the (last) 12th ribs in a population in a setting of detailed 2nd-trimester sonography using three-dimensional (3D) ultrasound and to assess whether or not this may be related to chromosomal aneuploidies.

METHODS

Prospectively, we counted fetal ribs for the absence of the (last) 12th ribs in singleton pregnancies of women who presented to our clinic for detailed 2nd-trimester sonography. The assessment was carried out using 3D ultrasound. Volume data sets were acquired with the 3D skeleton mode using the maximum intensity with X-ray-weighted rendering. If the 3D skeleton mode was not sufficient, volume contrast imaging with the OmniView bone mode was used.

RESULTS

The fetal ribs could be visualized in 97.01% of the 1,943 fetuses examined between 20 and 23 weeks' gestation. Timing the examination at 21, 22, or 23 weeks was found to be more successful than conducting it at 20 weeks. Twelfth ribs were found to be absent in 33 fetuses; 16 fetuses had 11 ribs unilaterally and 17 had so bilaterally. None of them had chromosomal abnormalities. Associated anomalies were present in 6 fetuses (18.2%); 2 of the anomalies were major and 4 minor.

CONCLUSION

The incidence of absent 12th ribs in this mixed population was 1.75%. In the absence of additional anomalies, the prognosis is favorable.

Increased prevalence of abnormal vertebral patterning in fetuses and neonates with trisomy 21

PURPOSE

To assess the prevalence of an abnormal number of ribs in a cohort of fetuses and neonates with trisomy 21 and compare this with a subgroup of fetuses without anomalies.

MATERIALS AND METHODS

Radiographs of 67 deceased fetuses, neonates, and infants that were diagnosed with trisomy 21 were reviewed. Terminations of pregnancy were included. The control group was composed of 107 deceased fetuses, neonates, and infants without known chromosomal abnormalities, structural malformations, infections or placental pathology. Cases in which the number of thoracic ribs or presence of cervical ribs could not be reliably assessed were excluded. The literature concerning vertebral patterning in trisomy 21 cases and healthy subjects was reviewed.

RESULTS

Absent or rudimentary 12th thoracic ribs were found in 26/54 (48.1%) cases with trisomy 21 and cervical ribs were present in 27/47 (57.4%) cases. This prevalence was significantly higher compared to controls (28/100, 28.0%, Χ²(1) = 6.252, p = .012 and 28/97, 28.9%, Χ²(1) = 10.955, p < .001, respectively).

CONCLUSIONS

Rudimentary or absent 12th thoracic ribs and cervical ribs are significantly more prevalent in deceased fetuses and infants with trisomy 21.

Vertebral abnormality without spine-curvature deformity on prenatal ultrasonography: sonographic findings and postnatal radiographic correlations

PURPOSE

To evaluate prenatal US features and postnatal radiographic findings of fetuses with a sonographically detected vertebral abnormality (VA) without spine-curvature deformity (SCD).

METHODS

Twenty-six fetuses showing a VA without SCD on prenatal US at our ultrasound center for a 5-year period were retrospectively identified and evaluated for sonographic data and coexisting anomalies. Medical records and postnatal radiographs of all 16 live births were reviewed.

RESULTS

Coexisting major anomalies were suspected prenatally in 8/26 fetuses (30.8%). Sonographic abnormalities were noted in the vertebral body in 27/31 (87.1%) and in the posterior element in 4/31 (12.9%). US features were absent (n = 2) or small vertebral body echo (n = 21), two separate vertebral body echoes (n = 4), or smaller or lobulated posterior arch echoes (n = 4). Among 16 live-born neonates, postnatal radiographs revealed a vertebral abnormality in 20 (95.2%) of 21 prenatally detected VA without SCD. The abnormalities were vertebral body hypoplasia (18/19) with an incomplete sagittal cleft, asymmetric/unilateral hypoplasia, or hypoplasia with a complete sagittal cleft; or abnormalities in the spinous process (2/2).

CONCLUSIONS

Most fetuses with prenatally detected VA without SCD had hypoplastic vertebrae on postnatal radiographs. Prenatal recognition of VA without SCD can lead to an early postnatal diagnosis of a vertebral abnormality and guidance for follow-up.

Paleodysmorphology and paleoteratology: Diagnosing and interpreting congenital conditions of the skeleton in anthropological contexts

Most congenital conditions have low prevalence, but collectively they occur in a few percent of all live births. Congenital conditions are rarely encountered in anthropological studies, not least because many of them have no obvious effect on the skeleton. Here, we discuss two groups of congenital conditions that specifically affect the skeleton, either qualitatively or quantitatively. Skeletal dysplasias (osteochondrodysplasias) interfere with the histological formation, growth and maturation of skeletal tissues leading to diminished postural length, but the building plan of the body is unaffected. Well- known skeletal dysplasias represented in the archeological record include osteogenesis imperfecta and achondroplasia. Dysostoses, in contrast, interfere with the building plan of the body, leading to e.g. missing or extraskeletal elements, but the histology of the skeletal tissues is unaffected. Dysostoses can concern the extremities (e.g., oligodactyly and polydactyly), the vertebral column (e.g., homeotic and meristic anomalies), or the craniofacial region. Conditions pertaining to the cranial sutures, i.e., craniosynostoses, can be either skeletal dysplasias or dysostoses. Congenital conditions that are not harmful to the individual are known as anatomical variations, several of which have a high and population-specific prevalence that could potentially make them useful for determining ethnic origins. In individual cases, specific congenital conditions could be determinative in establishing identity, provided that ante-mortem registration of those conditions was ensured. Clin. Anat. 29:878-891, 2016. © 2016 The Authors Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.