What are the signs and symptoms of Focal dermal hypoplasia? Focal dermal hypoplasia is usually evident from birth and primarily affects the skin, skeleton, eyes, and face. The signs and symptoms of vary widely, although almost all affected individuals have skin abnormalities. Some of the skin findings include streaks of very thin skin (dermal hypoplasia), yellowish-pink nodules of fat under the skin, areas where the top layers of skin are absent (cutis aplasia), telangiectases, and streaks of slightly darker or lighter skin. These skin features can cause pain, itching, irritation, or lead to skin infections. With age, most develop wart-like growths, called papillomas, around the nostrils, lips, anus, and female genitalia. They may also be present in the throat, specifically in the esophagus or larynx, and can cause problems with swallowing, breathing, or sleeping. Other features include small, ridged fingernails and toenails as well as sparse, brittle or absent scalp hair. The skeleton is usually affected as well. Many individuals have hand and foot abnormalities, including missing fingers or toes (oligodactyly), webbed or fused fingers or toes (syndactyly), and a deep split in the hands or feet with missing fingers or toes and fusion of the remaining digits (ectrodactyly). X-rays can show streaks of altered bone density, called osteopathia striata, which usually do not cause symptoms.  Eye abnormalities are common and can include microphthalmia and anopthalmia as well as problems with the tear ducts. The retina or the optic nerve can also be incompletely developed, which can result in a gap or split in these structures (coloboma). Some of these eye abnormalities do not impair vision, while others can lead to low vision or blindness. People with focal dermal hypoplasia often have distinctive, but subtle facial features such as a pointed chin, small ears, notched nostrils, and a slight difference in the size and shape of the right and left sides of the face (facial asymmetry). Some individuals may have a cleft lip and/or palate. About half of those with focal dermal hypoplasia have teeth abnormalities of their teeth, especially of the enamel (the hard, white material that forms the protective outer layer of each tooth). Less commonly, kidney and gastrointestinal abnormalities are present. The kidneys may be fused together, which can lead to kidney infections. The main gastrointestinal abnormality that is seen is an omphalocele. The Human Phenotype Ontology provides the following list of signs and symptoms for Focal dermal hypoplasia. 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 dental enamel 90% Abnormality of dental morphology 90% Abnormality of epiphysis morphology 90% Abnormality of the nail 90% Camptodactyly of finger 90% Dermal atrophy 90% Finger syndactyly 90% Hand polydactyly 90% Hypermelanotic macule 90% Lower limb asymmetry 90% Low-set, posteriorly rotated ears 90% Reduced number of teeth 90% Rough bone trabeculation 90% Split foot 90% Split hand 90% Telangiectasia of the skin 90% Thin skin 90% Toe syndactyly 90% Verrucae 90% Abnormal localization of kidney 50% Abnormality of pelvic girdle bone morphology 50% Abnormality of the clavicle 50% Abnormality of the ribs 50% Alopecia 50% Aplasia/Hypoplasia of the iris 50% Choroideremia 50% Cognitive impairment 50% Dental malocclusion 50% Ectopia lentis 50% Facial asymmetry 50% Iris coloboma 50% Multicystic kidney dysplasia 50% Opacification of the corneal stroma 50% Scoliosis 50% Spina bifida 50% Strabismus 50% Abdominal pain 7.5% Abnormality of adipose tissue 7.5% Abnormality of the mediastinum 7.5% Abnormality of the pulmonary vasculature 7.5% Acute hepatic failure 7.5% Aplasia/Hypoplasia of the lungs 7.5% Congenital diaphragmatic hernia 7.5% Duodenal stenosis 7.5% Narrow nasal bridge 7.5% Neoplasm of the skeletal system 7.5% Omphalocele 7.5% Patent ductus arteriosus 7.5% Pointed chin 7.5% Renal hypoplasia/aplasia 7.5% Umbilical hernia 7.5% Ventricular septal defect 7.5% Abnormality of the larynx - Abnormality of the pinna - Absent fingernail - Absent toenail - Agenesis of corpus callosum - Aniridia - Anophthalmia - Anteriorly placed anus - Arnold-Chiari malformation - Bifid ureter - Brachydactyly syndrome - Brittle hair - Broad nasal tip - Chorioretinal coloboma - Cleft ala nasi - Cleft palate - Cleft upper lip - Clitoral hypoplasia - Congenital hip dislocation - Cryptorchidism - Delayed eruption of teeth - Diastasis recti - Foot polydactyly - Hiatus hernia - Horseshoe kidney - Hydrocephalus - Hydronephrosis - Hypodontia - Hypoplasia of dental enamel - Hypoplastic nipples - Inguinal hernia - Intellectual disability - Intestinal malrotation - Joint laxity - Labial hypoplasia - Linear hyperpigmentation - Low-set ears - Microcephaly - Microphthalmia - Midclavicular aplasia - Midclavicular hypoplasia - Mixed hearing impairment - Myelomeningocele - Nail dysplasia - Nystagmus - Oligodactyly (feet) - Oligodactyly (hands) - Oligodontia - Optic atrophy - Osteopathia striata - Patchy alopecia - Postaxial hand polydactyly - Reduced visual acuity - Reticular hyperpigmentation - Short finger - Short metacarpal - Short metatarsal - Short phalanx of finger - Short ribs - Short stature - Sparse hair - Spina bifida occulta - Stenosis of the external auditory canal - Supernumerary nipple - Telangiectasia - Ureteral duplication - Visual impairment - X-linked dominant inheritance - 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.