Others: polydactyly (an excess of fingers or toes), syndactyly (fused fingers or toes), brachydactyly (short fingers and/or toes), clinodactyly (bending of the fifth fingers towards the fourth fingers), preauricular skin tags, an absent tragus, low set ears, deafness, small frontal sinuses, mental retardation, encephalocele (protrusion of the brain), spina bifida (split spine), meningoencephalocele (protrusion of both meninges), umbilical hernia, cryptorchidism (absence of one or two testes) and possibly cardiac anomalies.The clefts of the face that are present in FND are vertical clefts. These can differ in severity. When they are less severe, they often present with hypertelorism and normal brain development. Mental retardation is more likely when the hypertelorism is more severe or when extracephalic anomalies occur. Cause
Embryogenesis
Midline facial clefts are one of the symptoms in FND. These defects develop in the early stages of embryological development. This is around the 19th to 21st day of pregnancy. The cause of the defect is failure of the mesodermal migration. The mesoderm is one of the germ layers (a collection of cells that have the same embryological origin). As a result of this failure, a midline facial cleft is formed.Another symptom of FND is the V-shaped hairline. In the normal situation, hair growth surrounding the eyes is inhibited. However, in FND this suppression is prevented in the midline by the increased inter-ocular distance. This causes the so-called widow’s peak (a V-shaped hairline) in FND patients.Very early in embryogenesis, the face and neck develop. This development continues until adolescence.
The other with hypotelorism (a decreased distance between the eyes), this includes holoprosencephaly (failure of development of the forebrain). In addition, a craniofacial cleft can be classified using the Tessier classification. Each of the clefts is numbered from 0 to 14. The 15 different types of clefts are then subdivided into 4 groups, based on their anatomical position in the face: midline clefts, paramedian clefts, orbital clefts and lateral clefts. FND is a midline cleft, classified as Tessier 0/14. Besides this, the additional anomalies seen in FND can be subdivided by region. None of these anomalies are specific for the syndrome of FND, but they do occur more often in patients with FND than in the population. The anomalies that may be present are:

Nasal: mild anomalies to nostrils that are far apart and a broad nasal root, a notch or cleft of the nose and accessory nasal tags. Ocular: narrowed eye slits, almond shaped eyes, epicanthal folds (extra eyelid tissue), epibulbar dermoids (benign tumors of the eye), upper eyelid colombas (full thickness upper eyelid defects), microphthalmos (one or two small eyes), congenital cataract and degeneration of the eye with retinal detachment. Facial: telecanthus (an increased distance between the corners of the eye), a median cleft of the upper lip and/or palatum, and a V-shaped hairline.