Introduction
Phocomelia is an extremely rare congenital disorder involving the limbs (dysmelia). Étienne
Geoffroy Saint-Hilaire coined the term in 1836. The word “phocomelia” means seal limb.
There are several ways in which phocomelia may develop in utero. One is a spontaneous
genetic mutation, usually triggered by environmental pressures. Notoriously, the drug
thalidomide which was once prescribed for nausea and to alleviate morning sickness in
pregnant women can cause phocomelia. Once people stopped prescribing this medication to
pregnant women, the incidence of phocomelia went down dramatically.
We present case of phocomelia in which cause may be genetic mutation as there was no
history of any drug intake.
Case report
20 years old Primigravida with h/o 9 months amenorrhea came with c/o pain in abdomen. No
other complains. . Her present pregnancy was unregister and not immunized. She had 2nd
degree non consanguineous marriage. No history of any drug intake during antennal period
.On examination her general condition was stable .On pre abdomen examination uterus was
full term cephalic presentation fixed FHS 140beatsper mins. On per vaginal examination
cervix was 6cm dilated 80%effiaced station o. patient delivered after 4 and half hr
On examination of baby
Female, cried immediately after birth, weight 2.2 kg, baby having left forearm absent.
Discussion
A developmental anomaly characterized by absence of the upper part of one or more of the
limbs so that the feet or hands or both are attached to the trunk of the body by short,
irregularly shaped stumps, resembling the fins of a seal. The condition, caused by
interference with the embryonic development of the long bones, is rare and is seen primarily
as a side effect of the drug thalidomide taken during early pregnancy. Also called seal limbs.
Phocomelia is a form of birth defect in which the long bones in one or more limbs are
missing or shortened. As a result, the entire limb is foreshortened. The limb may appear
flipperlike, explaining the name, which is derived from the root words for “seal” and “limb.”
This birth defect is quite rare. Children born with this condition may require surgery to
address other abnormalities which sometimes occur concurrently with phocomelia.
There are several ways in which phocomelia may develop in utero. One is a spontaneous
genetic mutation, usually triggered by environmental pressures and other is drug induced. In
the late 1950s, thalidomide was available by prescription only. The medication was used to
fight anxiety and stress related problems. By the end of the 1950s, the drug was also being
used in pregnant women who had trouble controlling morning sickness and nausea. In 1960,
the drug was released as an over the counter medication and women no longer needed a
prescription to take the thalidomide. The result was fatal for some babies and deforming for
others.1Thalidomide became effectively linked to death or severe disabilities among babies.
Those subjected to thalidomide while in the womb experienced limb deficiencies in a way
that the long limbs either were not developed or presented themselves as stumps. Other
effects included: deformed eyes, hearts, alimentary, and urinary tracts, and blindness and
deafness.
The drug thalidomide is directly related to birth defects. Thalidomide also caused absence of
the radial ray (radius and thumb), malformations of the eyes, ears, heart, kidneys and nervous
system. Today, doctors understand that thalidomide can be used in certain medical cases but
it is no longer prescribed to pregnant women due to the increased risk of miscarriage and
phocomelia. When taking thalidomide during pregnancy, the fetus was self aborted in 50% of
the cases.
Clinical Findings

Effects of drug were usually bilateral, especially in upper extremity

Upper extremities were more affected than lower

The upper extremity bones affected are, in order:

Thumbs (complete absence is most frequent)

Radius (may be short and bowed)

Humerus (like radius, is affected from distal to proximal)

Ulna

Fingers 3, 4 and 5
The gene that causes Phocomelia is a recessive gene. Phocomelia is transmitted as an
autosomal recessive trait with variable expressivity and malformation is linked to
chromosome 8. This means both parents need to have the same gene in order for the
characteristics of the birth defect to appear. If one parent has the gene and the other parent
does not, the recessive nature of the gene stops the defect from occurring. As a matter of fact,
only 25% of the pregnancies between two recessive gene carriers will show the signs of
phocomelia. Having one of more foreshortened limbs does not necessarily mean that one will
pass the trait on, or that the trait will manifest in exactly the same way in a child. Genetics
can be very complicated, and the interactions of several recessive genes can be involved in
the expression of phocomelia. People who are concerned can talk to a genetic counselor
about the specifics of their case and their concerns
The occurrence of this malformation in an individual results in various abnormalities to the
face, limbs, ears, nose, vessels and many other underdevelopments. The best fix for
phocomelia is prevention of a pregnant woman taking thalidomide during pregnancy and
prosthesis. Although operations can be done to fix the abnormality it is difficult due to the
lack of nerves, bones, and other related structures.
How thalidomide cause limb defect is still unknown. But various Hypotheses were kept to
find out how it causes limb defect. Thalidomide embryopathy-proposed mechanism of action
is that it inhibits the transcription of genes which are necessary for angiogenesis. Inhibition of
the genes interferes with normal angiogenesis, which results in truncation of the limb2.
Thalidomide is an immunomodulatory agent, which arrests angiogenesis. The mechanism of
anti-angiogenic activity of thalidomide is not fully understood. As nitric oxide is involved in
angiogenesis.Thalidomide attenuates nitric oxide mediated angiogenesis by blocking
migration of endothelial cells 3
Conclusion
All congenital anomalies can detected at about 18 to20 weeks of gestations. So anomaly scan
at this gestation is very important. We should advise to every pregnant woman to have at
least one anomaly scan at 18 to 20 weeks of gestation.
1 Phocomelia. Available from: http:// en.wikipedia.org/wiki/phocomelia
2 STEPHENS TD, FILLMORE BJ TERATOLOGY. 2000 MAR; 61(3):189-95
3 KP Tamilarasan, Gopi K Kolluru, Megha Rajaram, M Indhumathy, R Saranya and Suvro
Chatterjee BMC Cell Biology 2006, 7:17