What are the signs and symptoms of Cohen syndrome? The signs and symptoms of Cohen syndrome may vary greatly from person to person. Some studies have suggested that a large number of people with Cohen syndrome have similar facial features regardless of ethnic background, including thick hair and eyebrows, long eyelashes, wave-shaped palpebral fissures, broad nasal tip, smooth or shortened philtrum, and hypotonic appearance.  Other findings that tend to be more common among almost all people with Cohen syndrome are listed below. Retinal dystrophy (a condition in which the muscles of the retina do not work properly) Progressive high myopia (nearsightedness) Acquired microcephaly (smaller than normal-sized head) Non-progressive mental retardation, global developmental delay Hypotonia Joint hyperextensibility (unusually large range of joint movement) The Human Phenotype Ontology provides the following list of signs and symptoms for Cohen syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormality of neutrophils 90% Abnormality of the eyelashes 90% Abnormality of the palate 90% Aplasia/Hypoplasia of the tongue 90% Arachnodactyly 90% Chorioretinal abnormality 90% Cognitive impairment 90% Gingival overgrowth 90% Hypoplasia of the zygomatic bone 90% Long toe 90% Low anterior hairline 90% Microcephaly 90% Muscular hypotonia 90% Myopia 90% Neurological speech impairment 90% Open mouth 90% Prominent nasal bridge 90% Reduced number of teeth 90% Sandal gap 90% Short philtrum 90% Tapered finger 90% Thick eyebrow 90% Abnormality of the voice 50% Clinodactyly of the 5th finger 50% Coarse hair 50% Cubitus valgus 50% Finger syndactyly 50% Genu valgum 50% Intrauterine growth retardation 50% Joint hypermobility 50% Macrodontia 50% Obesity 50% Prenatal movement abnormality 50% Short stature 50% Abnormality of retinal pigmentation 7.5% Abnormality of the hip bone 7.5% Abnormality of the mitral valve 7.5% Aplasia/Hypoplasia affecting the eye 7.5% Aplasia/Hypoplasia of the earlobes 7.5% Cryptorchidism 7.5% Iris coloboma 7.5% Kyphosis 7.5% Nystagmus 7.5% Optic atrophy 7.5% Pectus excavatum 7.5% Preauricular skin tag 7.5% Seizures 7.5% Sensorineural hearing impairment 7.5% Strabismus 7.5% Ventricular septal defect 7.5% Autosomal recessive inheritance - Cerebellar hypoplasia - Childhood-onset truncal obesity - Chorioretinal dystrophy - Convex nasal ridge - Delayed puberty - Facial hypotonia - Feeding difficulties in infancy - Growth hormone deficiency - High, narrow palate - Hypoplasia of the maxilla - Intellectual disability - Laryngomalacia - Leukopenia - Lumbar hyperlordosis - Macrodontia of permanent maxillary central incisor - Mitral valve prolapse - Motor delay - Neonatal hypotonia - Neutropenia - Pes planus - Reduced visual acuity - Short metacarpal - Short metatarsal - Single transverse palmar crease - Small for gestational age - Thick corpus callosum - Thoracic scoliosis - Visual impairment - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.