What are the signs and symptoms of Dandy-Walker like malformation with atrioventricular septal defect? The Human Phenotype Ontology provides the following list of signs and symptoms for Dandy-Walker like malformation with atrioventricular septal defect. 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 the fontanelles or cranial sutures 90% Cognitive impairment 90% Dandy-Walker malformation 90% Frontal bossing 90% Hypertelorism 90% Muscular hypotonia 90% Neurological speech impairment 90% Wide nasal bridge 90% Abnormality of the aorta 50% Abnormality of the mitral valve 50% Abnormality of the pulmonary artery 50% Abnormality of the tricuspid valve 50% Aplasia/Hypoplasia of the cerebellum 50% Atria septal defect 50% Cleft palate 50% Complete atrioventricular canal defect 50% Depressed nasal bridge 50% Hydrocephalus 50% Hypoplastic left heart 50% Kyphosis 50% Low-set, posteriorly rotated ears 50% Macrocephaly 50% Prominent occiput 50% Recurrent respiratory infections 50% Scoliosis 50% Short nose 50% Short stature 50% Tetralogy of Fallot 50% Ventricular septal defect 50% Abnormality of neuronal migration 7.5% Abnormality of the fingernails 7.5% Abnormality of the hip bone 7.5% Abnormality of the ribs 7.5% Abnormality of the upper urinary tract 7.5% Aplasia/Hypoplasia of the nipples 7.5% Brachydactyly syndrome 7.5% Chorioretinal coloboma 7.5% Displacement of the external urethral meatus 7.5% Ectopic anus 7.5% Finger syndactyly 7.5% Glaucoma 7.5% Hand polydactyly 7.5% Hernia of the abdominal wall 7.5% Hypoplasia of penis 7.5% Intestinal malrotation 7.5% Iris coloboma 7.5% Optic atrophy 7.5% Preauricular skin tag 7.5% Primary adrenal insufficiency 7.5% Short neck 7.5% Single umbilical artery 7.5% Urogenital fistula 7.5% Vertebral segmentation defect 7.5% Adrenal hypoplasia - Anal atresia - Aortic valve stenosis - Autosomal recessive inheritance - Brachycephaly - Coloboma - Double outlet right ventricle - Growth hormone deficiency - Hemivertebrae - High forehead - Hydronephrosis - Hypospadias - Intrauterine growth retardation - Low posterior hairline - Low-set ears - Missing ribs - Posterior fossa cyst - Pulmonic stenosis - Syndactyly - 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.