Introduction
The recurrent spontaneous abortion (RSA) is known complication of pregnancy. The cause is multifactorial and associated with parental age, infectious diseases, congenital anomalies and genetic abnormalities (Dudley and Brauch, 1989). RSA is historically defined as three or more consecutive pregnancy losses before 20 to 22 weeks of gestation (Stirrat, 1990).

Balanced translocations are frequent structural chromosomal rearrangements observed in humans.  The usual translocations reported are between X chromosome and autosomes. The most frequently chromosomes involved are 4, 6, 9, 12, 15 and 18 (Tullu et al., 2001).

Around 15 to 20% of all pregnancies in human end up with spontaneous abortions (SABs).

The incidence of chromosomal abnormalities in those abortions is around 50%. Although the causes is unknown but parental chromosomal anomalies is one of the possible cause for RSA.

Case Report
A 28-year old female patient reported to our cytogenetic laboratory with history of three times recurrent spontaneous abortions. There was no bad obstetrics history in family. Her height was normal 154 cm and weight was 58 kg having no consanguinity. She had well developed secondary sexual characters.

Chromosomal analysis was conducted on heparinized blood samples of both male and female by PHA-stimulated blood cultures. Chromosome preparation were subjected to GTG-banding (Seabright, 1971) and preparation of karyotyped was done according to ISCN (2009).

The results showed balanced translocation between long arm of chromosome 4 and short arm of chromosome 20. A karyotype of 46,XX,t(4;20)(q11; p13) was revealed (Figure 1) with clinically normal looking female phenotype, while male partner has a normal genotype with 46,XY.
 

Discussion
Cytogenetic anomalies have known to cause male and female infertility, but the exact mechanism by which how chromosomal anomalies induce infertility is yet to be proved. Several reports indicated that the chromosomal abnormalities which ranges from 2.2% to 15.7% for infertile men and an around 15 to 20% of all pregnancies in human end in spontaneous abortions (De et al., 2015).

In the current case report, we present a family of which a male apparently healthy with 46,XY chromosome complement while female has three recurrent spontaneous abortions (RSA). A karyotype of female revealed a balanced translocation t(4;20) with break points of 4q11 and 20p13. To best of our knowledge balanced translocation t(4;20) with break points (q11;p13) is a novel one and completely different from one reported by Nigam et al., (2014).

They have revealed balanced t(4;20) (q12;q13.1) with absence of endometrium and primary amenorrhea. In our study, we found presence of endometrium without primary amenorrhea instead she had three times RSA and her phenotype was completely normal. Therefore, we suggest that such novel cases with normal phenotype be reported for better understanding of involving autosomal balanced chromosomal abnormalities in infertility.

Conclusion
The present study reported a novel balanced translocation [t(4;20)] could be one of the reasons for a recurrent spontaneous abortion. Hence, cytogenetic analysis should be mandatory for all couples with reproductive failures along with adequate genetic counselling to make informed decision regarding subsequent pregnancies.

Ethical Clearance
The ethical clearance was obtained from Institutional ethical committee.

Author’s Contribution
The work was carried out in collaboration. Author PG designed study, wrote protocol and prepared first draft of MS. Author SV performed culture and microscopic analysis and made preparation of karyotypes. PG managed the literature searches and analysis of data. Both authors read and approved the final MS.

References
De P, Chakravarty S., and Chakravarty A., 2015, Novel balanced translocations in females with recurrent spontaneous abortions: Two case studies, J. Humn. Reprod Sci., 8(2): 114-117
http://dx.doi.org/10.4103/0974-1208.158623

Dudley D.J., and Brauch D.W., 1989, New approach to recurrent pregnancy loss, Clin. Obst., 32: 20-32

ISCN, 2009, An International system for human cytogenetic nomenclature

Nigam A., Ahmad A., and Batra S., 2014, Absent endometrium due to balanced, translocation [t(4;20)] presenting as primary amenorrhea, J. Humn. Reprod Sci., 7(1): 63–65
http://dx.doi.org/10.4103/0974-1208.130867

Sea bright M., 1971, A rapid banding technique for human chromosome, Lancet, 2: 971-972

Stirrat G.M., 1990, Recurrent miscarriage, Lancet, 336: 673-675
http://dx.doi.org/10.1016/0140-6736(90)92159-F

Tullu M.S., Arora P., Parmar R.C., Mahajan M.N., and Bhamcho B.A., 2001, Ovarian dysgenesis with balanced  autosomal translocation, J. Postgrad Med., 47: 113-115