SNP Shot: Genomic Insights

Blepharocheilodontic (BCD) syndrome is a congenital condition, meaning it is present from birth. It primarily impacts the eyelids (indicated by "blepharo-"), the upper lip ("-cheilo-"), and the teeth ("-dontic").

Individuals with BCD syndrome typically exhibit ectropion, a condition where the lower eyelids turn outward, exposing the inner surface. Euryblepharon, or sagging of the lower eyelid away from the eye, can also occur. Lagophthalmia, the inability to fully close the eyelids, is another common feature. Some individuals may also have distichiasis, characterized by extra eyelashes growing on the upper eyelids. These abnormal eyelashes, which can range from a few to a full extra set, emerge from the inner lining of the eyelid rather than the edge. When these eyelashes contact the eyeball, they can damage the cornea. Additional characteristics may include widely spaced eyes (hypertelorism), a flattened facial appearance, and a prominent forehead.

Further features often associated with BCD syndrome include bilateral cleft lip (openings on both sides of the upper lip) and cleft palate (an opening in the roof of the mouth). Affected individuals may have fewer teeth than normal (oligodontia), and their teeth may be smaller and cone-shaped. These dental irregularities affect both primary and permanent teeth. Sparse, fine hair and abnormal nails are also frequently observed.

In some cases, individuals with BCD syndrome may present with other conditions, such as imperforate anus (a blocked anal opening), thyroid gland abnormalities (either malformation or absence), leading to hypothyroidism, or syndactyly (fused fingers or toes). In rare instances, limb reduction defects (incompletely formed arms or legs) or spina bifida (a spinal cord defect) may occur.

Inheritance:

BCD syndrome follows an autosomal dominant inheritance pattern. This means that having only one copy of the mutated gene in each cell is enough to cause the disorder. While some individuals inherit the mutated gene from an affected parent, others develop the condition due to a new, spontaneous mutation in the gene, with no prior family history of the disorder.