• The parents of an affected child are obligate heterozygotes (i.e., presumed to be carriers of one SGPL1 pathogenic variant based on family history).
• Heterozygotes (carriers) are asymptomatic and are not at risk of developing the disorder.
• If both parents are known to be heterozygous for an SGPL1 pathogenic variant, each sib of an affected individual has at conception a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.

Carrier testing for at-risk relatives requires prior identification of the SGPL1 pathogenic variants in the family.

• The optimal time for determination of genetic risk, clarification of carrier status, and discussion of the availability of prenatal/preimplantation genetic testing is before pregnancy.
• It is appropriate to offer genetic counseling (including discussion of potential risks to offspring and reproductive options) to young adults who are affected, are carriers, or are at risk of being carriers.

Once the SGPL1 pathogenic variants have been identified in an affected family member, prenatal testing and preimplantation genetic testing are possible.
Differences in perspective may exist among medical professionals and within families regarding the use of prenatal testing. While most centers would consider use of prenatal testing to be a personal decision, discussion of these issues may be helpful.