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,
Early ultrasound. If you've experienced problems, such as a previous miscarriage or bleeding in the first weeks of this pregnancy, your doctor or midwife may recommend an early ultrasound. This takes place when you're between six weeks and 10 weeks pregnant.irst trimester combined screening. At the same time, as your dating ultrasound, you will be offered combined screening, to check for abnormalities. This is made up of: If you turn out to be less than 11 weeks pregnant when you have your dating ultrasound you will need to rebook for your combined screening.