Ultimately, BBS is distinguished from Laurence-Moon syndrome based on which genes are affected. However, one of the genetic mutations that cause BBS has also been found in individuals with Laurence-Moon syndrome, which illustrates the difficulty in distinguishing the two. There are 14 types of BBS, each of which is caused by a different genetic mutation. These 14 genes are BBS1, BBS2, ARL6 / BBS3, BBS4, BBS5, MKKS / BBS6, BBS7, TTC8 / BBS8, B1 / BBS9, C12ORF58 / BBS10, TRIM / BBS11, C4ORF24 / FLJ35630/BBS12, FLJ20345 / MKS1, and CEP290.
An ultrasound in pregnancy can be either done as a âroutineâ ultrasound, usually between 18-20 weeks or it is done for specific reasons which usually depend at the time of pregnancy. There are essentially three different types of ultrasounds, depending on how much information is required. 1  The limited ultrasound,
Fetal ultrasound is the safest way to check for problems and get information about your fetus, such as its size and position. It does not use X-rays or other types of radiation that may harm your fetus. It can be done as early as the 5th week of pregnancy.ransvaginal ultrasound is generally done early in a pregnancy to determine fetal age or to detect a suspected ectopic pregnancy. It is occasionally done late in pregnancy to determine the location of the placenta or in a high-risk pregnancy to monitor the length of the cervix.