Fetal Skeletal Dysplasia- A Grey Suspicion

Congress:

ECR 2019

Poster Number:

C-3786

Type:

Educational Exhibit

Keywords:

Foetus, Education and training, eLearning, Education, Diagnostic procedure, Ultrasound, Echocardiography, CT, Oncology, Obstetrics (Pregnancy / birth / postnatal period), Foetal imaging

Authors:

H. Pruthi, J. SEN; Rohtak, Haryana/IN

DOI:

10.26044/ecr2019/C-3786

DOI-Link:

https://dx.doi.org/10.26044/ecr2019/C-3786

Fig. 1: Fig.1 shows biparietal diameter 90.7 mm (Macrocephaly)

Fig. 2: Fig.2 shows short femur length(23mm).

Fig. 3: Fig.3 shows narrow thorax (bell shaped)

Fig. 4: Fig.4 shows short humerus(21 mm)

Learning objectives

1)To review the imaging spectrum and various association of three major fetal skeletal dysplasia’s viz. Achondroplasia, Achondrogenesis and Thanatophoric dysplasia. 2) To learn about various pointers and clues on imaging to raise the suspicion of Skeletal Dysplasia.

Background

Skeletal dysplasia's are a heterogeneous group ofconditions associated with abnormalities of the skeleton ( bone, cartilage and growth plate- shape, size, and density)that manifest as abnormalities of the limbs, chest, or skull with evolving phenotypes because of genetic inheritance or new mutations(de novo). (1) There are more than 400 TYPES {32 GROUPS} CLASSIFICATION A)Lethal vs Non-lethal dysplasia. B)Rhizo/meso/acro/micromelic. Four main culprits-Thanatophoric, Osteogenesis Imperfecta, Achondroplasia, and Achondrogenesis ( 67%). (2) Achondroplasia and Thanatophoricdysplasia(Td) are autosomal dominant whereas Achondrogenesis being autosomal recessive. Osteogenesisimperfecta has both autosomal dominant...

Findings and procedure details

We here present fetal cases of Achondroplasia, Thanatophoric dysplasia and Achondrogenesis with different manifestations in antenatal ultrasound. The antenatal USG was done on all three patients and further confirmed on MRI. All three cases were followed postnatally. There are certain common findings which are commonly found in all three types like decreased chest to abdomen circumference ratio and few are specific to one of the types like clover shaped head in Thanatophoric dysplasia. Thanatophoric dysplasia and Achondrogenesis are lethal in utero however Achondroplasia is of...

Conclusion

If Short limbs, Low nasal bridge then look for cranium and spine…. Achondroplasia- Large cranium with canal stenosis. Achondrogenesis- Hypoechoic normal cranium, incomplete ossification whole spine. Thanatophoric dysplasia- Clover cranium, telephone handle femur and Flat vertebrae (Platyspondyly). It is very challenging and difficult to diagnose a case of fetal skeletal dysplasia on sonography however with a high index of suspicion and relevant pointers major type of skeletal dysplasia can be diagnosed on a grey scale. Also rather than typing and further subtyping the skeletal dysplasia,...

Personal information

References

1.RimonDL, Lachman RS. The chondrodysplasias. In: Emery AEH, Rimon DL, eds. Emery and Rimoin’s principles and practice of medical genetics. New York, NY: Churchill Livingstone,1983; 703–733. 2.Camera G, Mastroiacovo P. Birth prevalence of skeletal dysplasias in the Italian multicentric monitoring system for birth defects. Progress in clinical and biological research. 1982;104:441-9. 3.Lachman RS, Rappaport V. Fetal imaging in the skeletal dysplasias. Clinics in perinatology. 1990 Sep 1;17(3):703-22. 4.Hadlock FP, Harrist RB, Shah Y, Park SK. The femur length/head circumference relation in obstetric sonography. Journal of...