SAT: Sperm Aneuploidy Test
(5 chromosomes: 13, 18, 21, X and Y)
1. What is the SAT test? The Sperm Aneuploidy Test (SAT) is a diagnostic test to study the genetic etiology of male infertility. In particular, this test evaluates the percentage of spermatozoa with chromosomal abnormalities in a sperm sample. This analysis allows the estimation of the transmission risk of chromosomal abnormalities to the offspring. This test analyzes the chromosomes mostly implicated in spontaneous miscarriages and affected offspring with chromosomal abnormalities (chromosomes 13, 18, 21, X and Y). 2. Objective. What is the usefulness of the test? At the clinical level, an increase in spermazoa with chromosomal abnormalities has been associated to a decrease in pregnancy rates and higher miscarriage risk in infertile couples undergoing after ICSI cycles (Rubio et al., 2001; Burrello et al., 2003; Petit et al., 2005; Nicopoullos et al., 2008; Rodrigo et al., 2011; Rodrigo et al., 2013). At the embryo level, different effects have been observed according tho the type of sperm chromosomal abnormality. An increase in the percentage of spermatozoa with sex chromosome disomies, results in an increase embryo aneuploides compatible with life (Patau Syndrome, Edwards Syndrome, Down Syndrome, Klinefelter Syndrome, Turner Syndrome and trisomies XXX and XYY). Whereas, an increase in diploid spermatozoa generates an increase in triploid embryos, that mostly miscarried before delivery (Rodrigo et al., 2010). At the offspring level, several studies performed in parents of Down, Kinefelter, and Turner syndrome children have shown increases in sperm chromosomal abnormalities associated to the chromosomopathies observed in the children (Eskenazi et al., 2002; Tanget al., 2004; Blanco et al., 1998). For these reasons, the Sperm Aneuploidy Test can help in the reproductive genetic counseling of the infertile men to assess the optimal assisted reproduction approach. 3. Indications. To whom and when? This is a diagnostic test directed to the study of male infertility, indicated to patients with higher sperm aneuploidy risk, that is, men with impaired sperm parameters, mainly oligozoospermia, non‐obstructive azoospermia, and severe teratozoospermia. Another indications, not necessarily associated to impaired sperm parameters are recurrent miscarriage of unknown etiology; couples failing to conceive after several IVF treatments and; couples with a previous pregnancy with chromosomopathy. 4. Advantages. Strengths among other tests? Compared to classic meiotic studies, this test offers the advantage of assessing the final product of meiosis, the spermatozoon that will directly fertilize the ovum. An average of 2,000 sperm per chromosome is analyzed by two independent observers to obtain clinically relevant results. The percentage of chromosomally abnormal sperm is compared to a control group of fertile normozoospermic donors to assess for statistical differences. 5. Sample. How? The SAT test can be performed in ejaculated samples and spermatozoa retrieved from the epididymis and testes. Ejaculated samples are obtained after masturbation in a sterile container. In the laboratory the sample is washed with buffered medium and can be stored in the fridge at 4ºC until processing. Spermatozoa retrieved from epididymis and testicle should be processed in a different way. The aspirated sperm or the testicular tissue fragments are placed in a Petri dish with washing medium and dilacerated with a scalpel, using the standard IVF protocols for testicular sperm extraction. 6. Shipping. How, when, where and who? The samples should be transported in special container at room temperature with a special packaging to prevent damage during transport. The sample should be addressed to: IVIGEN MIAMI IVIGEN LOS ANGELES 406 Amapola Avenue 7955 NW 12th St.Suite 415 Suite 215, Torrance, California 90501 Miami, Florida 33126 United States United States 7. Sample processing and reporting results. When? The evaluation of the sperm chromosomal abnormalities takes 2 weeks. Once the analysis is completed, a report is submitted to the patient or clinician. 8. Methodology The most important steps of the protocol are: 1) Sperm fixation in laboratory slides. 2) Decondensation of the sperm nuclei. 3) Hibridization with fluorescent DNA probes directly targeting the analyzed chromosomes. 4) Fluorescent signal detections, scoring and interpretation under an epifluorescent microscope equipped with specific filters. 9. Limitations This technique allows the detection of aneuploidy for the limited number of chromosomes included in the test. Seldom in few ejaculated samples or testicular samples, there is no enough spermatozoa for a proper estimation of the risk of aneuploidy. 10. How to start? Contact with: [email protected] 11. FAQ's What other chromosomes can be tested? If a previous chromosomal abnormality is detected in a previous pregnancy, a customized SAT test can be requested and additional FISH probes can be included in the test targeting the implicated chromosomes. Is sexual abstinence required before collecting the sperm sample for the test? A previous period of 2‐3 days of sexual abstinence is recommended before colleting the sample. Is there a minimal sperm concentration required to perform a SAT test? There is not a minimal concentration to request a sperm test, the only requirement is the presence of any sperm, even in a concentration below 1 million sperm/mL and also in samples from the epididymis or testes. Seldom there are not enough sperm to perform the test, and additional samples can be requested. Is it possible to perform a SAT test in carriers of structural abnormalities? It is possible to test sperm from carriers of translocations using DNA probes implicated in the chromosome rearrangement. 12. REFERENCES  Blanco J, Gabau E, Gómez D, Baena N, Guitart M, Egozcue J, Vidal F. Chromosome 21 disomy in the spermatozoa of the fathers of children with trisomy 21, in a population with a high prevalence of Down syndrome: increased incidence in cases of paternal origin. Am J Hum Genet. 1998 Oct; 63(4):1067‐72.  Burrello N, Vicari E, Shin P, Agarwal A, De Palma A, Grazioso C, D’Agata R, Calogero AE. Lower sperm aneuploidy frequency is associated with high pregnancy rates in ICSI programmes. Hum Reprod. 2003 Jul; 18(7):1371‐6.  Eskenazi B, Wyrobek AJ, Kidd SA, Lowe X, Moore D 2nd, Weisiger K, Aylstock M. Sperm aneuploidy in fathers of children with paternally and maternally inherited Klinefelter syndrome. Hum Reprod. 2002 Mar; 17(3):576‐
83.  Nicopoullos JD, Gilling‐Smith C, Almeida PA, Homa S, Nice L, Tempest H, Ramsay JW. The role of sperm aneuploidy as a predictor of the success of intracytoplasmic sperm injection?. Hum Reprod. 2008 Feb; 23(2):240‐50.  Petit FM, Frydman N, Benkhalifa M, Le Du A, Aboura A, Fanchin R, Frydman R, Tachdjian G. Could sperm aneuploidy rate determination be used as a predictive test before intracytoplasmic sperm injection?. J Androl. 2005 Mar‐Apr; 26(2):235‐41.  Rodrigo L, Peinado V, Mateu E, Remohí J, Pellicer A, Simón C, Gil‐Salom M, Rubio C. Impact of different patterns of sperm chromosomal abnormalities on the chromosomal constitution of preimplantation embryos. FertilSteril. 2010 Sep; 94(4):1380‐6.  Rodrigo L, Rubio C, Mateu E, Peinado V, Milán M, Viloria T, Al‐Asmar N, Mercader A, Buendía P, Delgado A, Escrich L, Martínez‐Jabaloyas JM, Simón c, Gil‐Salom M. FISH on sperm to identify infertile male patients with higher aneuploidy risk. Hum Reprod. 2013 June; 28(S1). Abstract:P‐458.  Rodrigo L, Rubio C, Peinado V, Villamón R, Al‐Asmar N, Remohí J, Pellicer A, Simón C, Gil‐Salom M. Testicular sperm from patients with obstructive and non obstructive azoospermia: aneuploidy risk and reproductive prognosis using testicular sperm from fertile donors as control samples. FertilSteril. 2001 Mar 1; 95(3):1005‐
12.  Rubio C, Gil‐Salom M, Simón C, Vidal F, Rodrigo L, Mínguez Y, Remohí J, Pellicer A. Incidence of sperm chromosomal abnormalities in a risk population: relationship with sperm quality and ICSI outcome. Hum Reprod. 2001 Oct; 16(10):2084‐92.  Tang SS, Gao H, Robinson WP, Ho Yuen B, Ma S. An association between sex chromosomal aneuploidy in sperm and an abortus with 45,X of paternal origin: possible transmission of chromosomal abnormalities through ICSI. Hum Reprod. 2004 Jan; 19(1):147‐51.