What are the signs and symptoms of Chromosome 3p- syndrome? The signs and symptoms of chromosome 3p- syndrome and the severity of the condition depend on the exact size and location of the deletion and which genes are involved. Some affected people appear to have no features or mild features, while others are more severely affected. Common symptoms shared by many people with this condition include: Growth problems both before and after birth Feeding difficulties Developmental delay Poor muscle tone (hypotonia) Intellectual disability Ptosis Distinctive facial features Microcephaly and/or unusual head shape Autism spectrum disorder Other features that may be seen include cleft palate; extra fingers and/or toes; gastrointestinal abnormalities; seizures; hearing impairment; kidney problems; and/or congenital heart defects. To read more about some of the signs and symptoms reported in people with 3p deletion syndrome, you can read Unique's disorder guide entitled '3p25 deletions.' The information in this guide is drawn partly from the published medical literature, and partly from Unique's database of members with a 3p deletion. The Human Phenotype Ontology provides the following list of signs and symptoms for Chromosome 3p- 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) Cognitive impairment 90% Hypertelorism 90% Long philtrum 90% Ptosis 90% Short stature 90% Telecanthus 90% Abnormality of calvarial morphology 50% Cleft palate 50% Complete atrioventricular canal defect 50% Cryptorchidism 50% Downturned corners of mouth 50% Epicanthus 50% Hearing impairment 50% Intrauterine growth retardation 50% Low-set, posteriorly rotated ears 50% Microcephaly 50% Muscular hypotonia 50% Postaxial hand polydactyly 50% Abnormality of periauricular region 7.5% Anteverted nares 7.5% Aplasia/Hypoplasia of the corpus callosum 7.5% Blepharophimosis 7.5% Clinodactyly of the 5th finger 7.5% Hypertonia 7.5% Sacral dimple 7.5% Seizures 7.5% Short neck 7.5% Thin vermilion border 7.5% Triangular face 7.5% Umbilical hernia 7.5% Ventriculomegaly 7.5% Abnormal renal morphology 5% Atrioventricular canal defect 5% Macular hypoplasia 5% Prominent nasal bridge 5% Autosomal dominant inheritance - Brachycephaly - Depressed nasal bridge - Feeding difficulties - Flat occiput - High palate - Low-set ears - Periorbital fullness - Postaxial polydactyly - Postnatal growth retardation - Preauricular pit - Prominent metopic ridge - Retrognathia - Spasticity - Synophrys - Trigonocephaly - Upslanted palpebral fissure - 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.