The second patient had no trace of mitral regurgitation (MR) in her family history, but had slight hypotonia. Patient three was the oldest at 36 who began to walk at age 3. She later gained weight at eleven and developed epilepsy in her late twenties. The fourth patient had problems associated with eating as a young child and was diagnosed with slowed development. Patient five had behavioural issues and struggled with MR in addition to being overweight. The geneticists discovered three new mutations within the EHMT1 gene. The first was an interstitial deletion, while the second and third were a nonsense and frameshift. Their findings supported the notion that a disruption in the EHMT1 gene contributes to the pathogenesis of Kleefstra syndrome.In another study published by the Journal of Medical Genetics, DNA from forty patients were extracted and subjected to MLPA, FISH or EHMT1 sequencing. The forty patients were divided into two groups: 1 group of 16 patients with the 9q34 deletion, and 1 group of 24 with typical FISH/MPLA results. The geneticists examined how a missense mutation would affect the function of the DNA by looking at DNA models. After, they screened each persons DNA using one of three tests, the results for the first group showed six patients had the same deletion of the same size (700 kb). In the second group, after EHMT1 sequencing was performed, six intragenic mutations were discovered. The scientists investigating this experiment conclude these mutations may be infective agents for the disease.
(2012), the mothers phenotype of the NM_024757.4:c.2712+1G>A mutation displayed mosaicism at certain tissues. This mutation resulted in the disregard of exon 18 on the EHMT1 gene, as opposed to removing it through the spliceosomes. In another transcript, however, an intron was placed between exon 18 and 19 of the EHMT1 gene. The combination of the intron insertion and the mosaicism in the mother was transferred to the child, resulting in the pathogenesis of the disease.In the past, research showed that the austerity of the disease was directly proportional to the number of EHMT1 deletions prevalent in an individual. The greater the deletions, the greater the severity of the condition. However, in recent studies, 9q34 deletion syndrome occurs when the EHMT1 gene is non-functioning, as opposed to strictly deletion. Diagnosis
Tests are either conducted at birth, or later in early childhood via: fluorescence in situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA), array comparative genomic hybridization (aCGH), and EHMT1 sequencing.FISH is a screening test that uses multicolour probes or comparative genomic hybridization to find any chromosome irregularities in a genome. It can be used for gene mapping, detecting aneuploidy, locating tumours etc. The multicolour probes attach to a certain DNA fragment. MLPA is a test that finds and records DNA copy change numbers through the use of PCR. MLPA can be used to detect tumours in the glial cells of the brain, as well as chromosomal abnormalities. Array-based comparative genomic hybridization (aCGH) tracks chromosome deletions and or amplifications using fluorescent dyes on genomic sequences of DNA samples.