‘Chromosome mutation cause of clubfoot’
COIMBATORE: In a one-of-its-kind multidisciplinary study, the Institute of Orthopaedics and Traumatology at Coimbatore Medical College Hospital (CMCH) has found out that two new mutated chromosomes were responsible for ‘isolated clubfoot’ among newborns.
What is clubfoot?
Clubfoot is a congenital condition in which the foot is twisted out of shape or position. It is characterised by structural changes of several tissues of the foot and lower leg. If left untreated, it can become a deformity and lead to gross disability.
Eye-opener
The study titled “Is congenital isolated clubfoot heritable? A study from India” authored by institute’s director S Vetrivel Chezhian and a postgraduate student Salmonkhan H was published in the Indian Journal of Orthopaedics Surgery recently.
The study noted down chromosome5:135031277 and chromosome5:135031344 mutations and their clinical significance have not yet been reported so far.
Speaking to TNIE, Vetrivel Chezian said not many studies have been conducted in India on clubfoot . There was a lone study done in the US. He said the study was done with a question of whether the isolated clubfoot deformity is heritable and also the other anomalies that are responsible for this condition in children.
“Until now, clubfoot was attributed to abnormal positioning of the embryo in the uterus. But, this study is an eye-opener as two new mutated chromosomes have been detected other than two already reported chromosomes,” he added.
Timeline
The study was undertaken from December 2019 to June 2020 as 50 isolated clubfoot babies were included in the study group, of which 32 were males and 18 were females.
Among 50 babies, Vetrivel said 23 had a bilateral clubfoot , 18 had right-sided and nine had a left-sided clubfoot . It is to be noted that clubfoot babies with other associated syndromes and other deformities are excluded from the study group.
He added, “We collected biological specimens from the babies and ran a few tests after isolating the DNA from blood samples. The DNA sequence was compared to the normal reference sequence. The reference sequence was obtained from genome databank of the National Centre for Biotechnology Information.”
The mutated chromosome5:135031277 was significantly associated with isolated non-syndromic clubfoot babies which is 2.26 times more likely to happen than the already reported chromosome5:135031290 mutation group, the result showed.
Need for a pan-India study
“Our study reveals the importance of establishing the genetic basis of isolated clubfoot in this modern era of science. A larger multicenteric study should be conducted in other regions of India to prepare a more specific gene to be associated with the clubfoot ,” Vetrivel added. The study was published online in June this year.
Nodal officer of State Neonatal Intensive Care Unit (NICU) S Srinivasan welcomed the study but opined that the findings had to be analysed further.
He said he could comment on the study only after going through it.
P Rathan, a public health expert, said genetic analysis must be done with a large sample size. “A wider study with genetical linkage would give us an insight about other sub-groups and population having the same chromosomes. We also need more of a geneticist, thus many medical professionals must be involved for genetic analysis,” he added.