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,
There are two ways of doing an ultrasound scan. In early pregnancy, especially before 11 weeks, it is usual to have a trans-vaginal (internal) scan, where a probe is placed in the vagina. This gives the clearest and most accurate picture in early pregnancy. It may also be offered after 11 or 12 weeks if a trans-abdominal scan doesnât give a clear enough picture. From 11 or 12 weeks, including at the routine booking-in scan, it is more common to have a trans-abdominal scan.