What are the signs and symptoms of Hennekam syndrome? The Human Phenotype Ontology provides the following list of signs and symptoms for Hennekam 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) Abnormal facial shape 90% Abnormality of dental morphology 90% Cognitive impairment 90% Decreased antibody level in blood 90% Delayed eruption of teeth 90% Depressed nasal bridge 90% External ear malformation 90% Hypertelorism 90% Increased number of teeth 90% Low-set, posteriorly rotated ears 90% Lymphangioma 90% Lymphedema 90% Lymphopenia 90% Malabsorption 90% Malar flattening 90% Reduced number of teeth 90% Abnormality of the genital system 50% Ascites 50% Broad forehead 50% Epicanthus 50% Erysipelas 50% Gingival overgrowth 50% Lymphadenopathy 50% Narrow chest 50% Recurrent respiratory infections 50% Seizures 50% Splenomegaly 50% Abnormal localization of kidney 7.5% Abnormality of neuronal migration 7.5% Abnormality of the foot 7.5% Abnormality of the pericardium 7.5% Abnormality of the pleura 7.5% Arteriovenous malformation 7.5% Benign neoplasm of the central nervous system 7.5% Camptodactyly of finger 7.5% Conductive hearing impairment 7.5% Craniosynostosis 7.5% Finger syndactyly 7.5% Glaucoma 7.5% Hydrops fetalis 7.5% Hypocalcemia 7.5% Narrow mouth 7.5% Pyloric stenosis 7.5% Respiratory insufficiency 7.5% Short philtrum 7.5% Atria septal defect - Autosomal recessive inheritance - Bilateral single transverse palmar creases - Camptodactyly - Conical incisor - Coronal craniosynostosis - Cryptorchidism - Cutaneous finger syndactyly - Delayed skeletal maturation - Ectopic kidney - Flat face - Hirsutism - Horseshoe kidney - Hydronephrosis - Hyperactivity - Hypoalbuminemia - Hypoplastic iliac wing - Intellectual disability - Intestinal lymphangiectasia - Joint contracture of the hand - Low-set ears - Mild postnatal growth retardation - Narrow palate - Oligodontia - Pachygyria - Pectus excavatum - Pericardial effusion - Pericardial lymphangiectasia - Periorbital edema - Pleural effusion - Pleural lymphangiectasia - Protein-losing enteropathy - Rectal prolapse - Retrognathia - Scoliosis - Sensorineural hearing impairment - Short foot - Short palm - Small hand - Smooth philtrum - Spina bifida occulta - Talipes equinovarus - Thyroid lymphangiectasia - Umbilical hernia - Ventricular septal defect - Vesicoureteral reflux - Wide nasal bridge - 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.