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Author information
Niphadkar M*, Parulekar
SV**
(* Second year resident,
** Professor and Head, Department of Obstetrics and Gynecology, Seth G.S
medical college and KEM hospital, Mumbai ,
India
Abstract
Skeletal dysplasias are
a very wide and diverse group of conditions related to abnormal bone growth and
development. The prenatal diagnosis by ultrasound is challenging due to wide variety of clinical
manifestations and changes occurring due to advancing gestational age. Most of
these babies are born at or near term.
Here we report an image of a second trimester fetal demise with the abortus
having abnormally short limbs.
Introduction
The most common type of
lethal skeletal dysplasia occurring in the neonatal period is thanatophoric
dyplasia. 1 These conditions pose a challenge for antenatal
sonography diagnosis because of large number of dysplasias, variability in time
at which the features appear, phenotypic variability with overlapping features
and lack of molecular diagnosis.
Case Report
A 24 year old woman,
married for 9 years (non-consanguineous marriage) , gravida 5, para 3, living
2, abortion 1, neonatal death 1 presented with 5 months of
amenorrhea. She was referred from a private hospital in view of ultrasonography
suggestive of intrauterine fetal demise at 14.5 weeks with malformed fetal
limbs. The patient had no complaints of pain in abdomen, bleeding per vaginum,
any bowel or bladder disturbances. She had no history of any significant medical
or surgical illness. Obstetric history was significant, as follows:
G1: female of 6 years, full term normal
delivery (FTND)
G2: female who died on day 1 of FTND. Patient
gave history that the baby had absent proximal limb bones.
G3: male of 1.5 years, FTND.
G4: spontaneous abortion at 2 month amenorrhea,
check curettage was done
G5: present pregnancy
The pregnancy was
terminated by induction with tablet Misoprostol 400 μg per vaginally 4 hourly.
The patient aborted with three doses. The abortus was found to have abnormally
short limbs (figure 1).
Figure 1. Abortus with
hupoplastic upper limbs.
It showed short, stunted
limbs, apparently missing proximal limb bones, without polydactyly or
syndactyly. It was somewhat macerated and its sex could not be determined. Its
long bones could not be assessed due to very less gestational age of the
abortus. Fetal karyotyping and fetal biopsy could not be done due to maceration
of tissues. After considering the history and examination of the abortus, the
most probable diagnosis of thanotophoric dysplasia, though osteogenesis
imperfecta type 2, achondroplasia and other less common dysplasias could not be
ruled out with certainty. The patient was explained regarding the autosomal
dominant inheritance of the condition resulting in 2 of her pregnancies getting
affected and was advised to avoid consanguineous marriages of her children to
avoid the future generations being affected by the condition.
Discussion
Skeletal
dysplasias are a wide heterogeneous group of conditions caused by disturbances
of bone growth, beginning in the early stages of fetal development and evolving
throughout life due to active gene involvement.[1] The osteochondrodysplasias are
disorders of development
and/or growth of
cartilage and/or bone, causing
affection of long bones in
a generalized and symmetric manner
and dwarfism. Various causes include thanatophoric dwarfism,
achondrogenesis, amelia, osteopetrosis, cleidocranial dysplasia, Ellis-van
Creveld syndrome, short rib polydactyly syndrome, Jarcho Levin syndrome,
femoral hypoplasia – unusual face syndrome, Ol type 1-3, spondyloepiphyseal
dysplasia congenital, SADDAN, fibrochondrogenesis etc.[1,2] Prenatal
diagnosis may be possible with ultrasonography (long bone measurements at or
less than the 5th centile or >3 SD below the mean.[3,4] Perinatal
lethality can be assessed by ultrasonographic chest circumference to abdominal
circumference ratio (<0.6) and/or femur length to abdominal circumference
measurement ratio (0.16). [3] Molecular testing helps identify homozygosity
or compound heterozygosity. Potdelivery/postmortem diagnosis can be done with
radiography, autopsy, histopathology and Immunohistochemistry. [3,4]
However if a patient aborts, the clinicians need to have knowledge of the
appearance of such fetuses so that the abortus can be studied further. The
published literature does not have many images of such abortuses. Hence this
image is presented.
References
- Dighe M, Fligner C, Cheng E, Warren B, Dubinsky T. Fetal Skeletal Dysplasia: An Approach to Diagnosis with Illustrative Cases. RSNA RadioGraphics 2008;28(4). DOI: http://dx.doi.org/10.1148/rg.284075122
- Krakow D, Rimoin DL. The skeletal dysplasias. Genetics in Medicine 2010;12:327–341.
- Krakow D, Lachman RS, Rimoin DL. Guidelines for the prenatal diagnosis of fetal skeletal dysplasias. Genet Med. 2009;11(2): 127–133. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2832320/
- Gnoli M, Pedrini E, Mordenti M, Tremosini M, Sangiorgi L. Skeletal dysplasias: approach to the clinical diagnosis and implication of appropriate diagnosis for knowledge and research studies in these rare diseases. Hereditary multiple Osteochondromas as example/paradigm. Italian Journal of Pediatrics 2014;40(Suppl 1):A8 doi:10.1186/1824-7288-40-S1-A8 Available from: http://www.ijponline.net/content/40/S1/A8
Citation
Niphadkar M, Parulekar SV. Skeletal Dysplasia: A prenatal
Diagnostic Challenge. JPGO 2015. Volume 2 No. 2. Available from: http://www.jpgo.org/2015/02/skeletal-dysplasia-prenatal-diagnostic.html