<s>[INST] I m about 18 weeks pregnant. I recenty had a amniocentesis in which the chromosomes results showed extra material on the chromosome 4. My husband and I had to give blood, the doctors said is either one of us carrier the trait it would be considered inherited from the parents. If neither one of us show the trait, should I be concered, and what health condition (disorders) could my baby have? [/INST] Hello and welcome to Chat Doctor. I am assuming that by "extra material in chromosome 4" you mean trisomy of chromosome 4. Please clarify it from your doctor. Trisomy chromosome 4 is a rare disorder. The baby may have structural deformity, cardiac malformations and mental retardation of varying degrees. If you and your partner both are carriers then chances of recurrence in future pregnancy is higher.in my opinion you should discuss this matter with your doctor about the possible effects to the fetus and decide prudently. Please write back if you have any more questions. </s>