Question: What is (are) Chromosome 3p- syndrome ?
Answer: Chromosome 3p- syndrome is a rare chromosome abnormality that occurs when there is a missing copy of the genetic material located towards the end of the short arm (p) of chromosome 3. The severity of the condition and the signs and symptoms 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 deletion include poor growth, developmental delay, intellectual disability, distinctive facial features, autism spectrum disorder, an unusually small head (microcephaly), and poor muscle tone (hypotonia). Most cases are not inherited, but people can pass the deletion on to their children. Treatment is based on the signs and symptoms present in each person.
Source: GARD

Question: What are the symptoms of Chromosome 3p- syndrome ?
Answer: 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.
Source: GARD

Question: What causes Chromosome 3p- syndrome ?
Answer: What causes chromosome 3p- syndrome? In most people with chromosome 3p- syndrome, the deletion occurs as a new mutation (called a de novo mutation) and is not inherited from a parent. De novo mutations are due to a random error that occurs during the formation of egg or sperm cells, or shortly after conception. In a few cases, the deletion is inherited from a parent.
Source: GARD

Question: How to diagnose Chromosome 3p- syndrome ?
Answer: How is chromosome 3p- syndrome diagnosed? There are several different specialized tests that can be used to diagnose a chromosome 3p- syndrome. These include: Karyotype - a karyotype is a laboratory test that produces an image of a person's chromosomes. This test can be used to diagnose large deletions. FISH - a laboratory technique that is used to detect and locate a specific DNA sequence on a chromosome. During FISH, a chromosome is exposed to a small DNA sequence called a probe that has a fluorescent molecule attached to it. The probe sequence binds to its corresponding sequence on the chromosome. This test can be used in combination with karyotyping for deletions that are too small to be seen on karyotype, alone. However, FISH is only useful if the person ordering the test suspects there is a duplication of a specific region of 3p. Array CGH - a technology that detects deletions that are too small to be seen on karyotype.
Source: GARD