What are the signs and symptoms of Acrocallosal syndrome, Schinzel type? The Human Phenotype Ontology provides the following list of signs and symptoms for Acrocallosal syndrome, Schinzel type. 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) Aplasia/Hypoplasia of the corpus callosum 100% Cognitive impairment 90% Duplication of phalanx of hallux 90% Duplication of thumb phalanx 90% Hypertelorism 90% Macrocephaly 90% Postaxial foot polydactyly 90% Postaxial hand polydactyly 90% Preaxial foot polydactyly 90% Preaxial hand polydactyly 90% Failure to thrive 75% Growth delay 75% Broad forehead 50% Dandy-Walker malformation 50% Epicanthus 50% Preauricular skin tag 50% Prominent occiput 50% Short nose 50% Sloping forehead 50% Triphalangeal thumb 50% Wide anterior fontanel 50% Finger syndactyly 33% Inguinal hernia 33% Toe syndactyly 33% Umbilical hernia 33% High palate 31% Short philtrum 31% Cleft palate 21% Cleft upper lip 21% Open mouth 16% Microretrognathia 14% Long philtrum 9% Thin vermilion border 9% Abnormality of the clavicle 7.5% Abnormality of the fontanelles or cranial sutures 7.5% Aplasia/Hypoplasia of the cerebellum 7.5% Congenital diaphragmatic hernia 7.5% Cryptorchidism 7.5% Displacement of the external urethral meatus 7.5% Hearing impairment 7.5% Hernia of the abdominal wall 7.5% Micropenis 7.5% Nystagmus 7.5% Posteriorly rotated ears 7.5% Sensorineural hearing impairment 7.5% Strabismus 7.5% Tall stature 7.5% Tapered finger 7.5% Coloboma 5% Optic atrophy 5% Hypoplasia of teeth 2% Smooth philtrum 2% Macrocephaly 25/27 Hypertelorism 24/26 Wide nasal bridge 24/26 Intellectual disability 23/25 Frontal bossing 23/26 Generalized hypotonia 20/23 Abnormality of the pinna 19/23 Hypospadias 10/18 Intracranial cystic lesion 10/27 Seizures 9/27 Abnormality of cardiovascular system morphology 5/22 Abnormality of the cardiac septa - Agenesis of corpus callosum - Anal atresia - Autosomal dominant inheritance - Autosomal recessive inheritance - Bifid distal phalanx of the thumb - Brachydactyly syndrome - Clinodactyly of the 5th finger - Heterogeneous - Hypopigmentation of the fundus - Intellectual disability, severe - Phenotypic variability - Postnatal growth retardation - Prominent forehead - Pulmonary valve defects - Rectovaginal fistula - Triangular mouth - 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.