Question: What is (are) Maternally inherited diabetes and deafness ?
Answer: Maternally inherited diabetes and deafness (MIDD) is a form of diabetes that is often accompanied by hearing loss, especially of high tones. The diabetes in MIDD is characterized by high blood sugar levels (hyperglycemia) resulting from a shortage of the hormone insulin, which regulates the amount of sugar in the blood. MIDD is caused by mutations in the MT-TL1, MT-TK, or MT-TE gene. These genes are found in mitochondrial DNA, which is part of cellular structures called mitochondria. Although most DNA is packaged in chromosomes within the cell nucleus, mitochondria also have a small amount of their own DNA (known as mitochondrial DNA or mtDNA). Because the genes involved with MIDD are found in mitochondrial DNA, this condition is inherited in a mitochondrial pattern, which is also known as maternal inheritance. Because egg cells, but not sperm cells, contribute mitochondria to the developing embryo, only females pass mitochondrial conditions to their children. Mitochondrial disorders can appear in every generation of a family and can affect both males and females, but fathers do not pass mitochondrial traits to their children.
Source: GARD

Question: What are the symptoms of Maternally inherited diabetes and deafness ?
Answer: What are the signs and symptoms of Maternally inherited diabetes and deafness? The Human Phenotype Ontology provides the following list of signs and symptoms for Maternally inherited diabetes and deafness. 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 macula 90% Chorioretinal abnormality 90% Constipation 90% Diabetes mellitus 90% Malabsorption 90% Sensorineural hearing impairment 90% Abnormality of lipid metabolism 50% Aplasia/Hypoplasia of the cerebellum 50% Arrhythmia 50% Congestive heart failure 50% Glomerulopathy 50% Hypertension 50% Hypertrophic cardiomyopathy 50% Muscle weakness 50% Myalgia 50% Ophthalmoparesis 50% Proteinuria 50% Cataract 7.5% Incoordination 7.5% Renal insufficiency 7.5% Retinopathy 7.5% Visual impairment 7.5% Ptosis 5% Dysarthria - External ophthalmoplegia - Hyperglycemia - Mitochondrial inheritance - Pigmentary retinal degeneration - Retinal degeneration - Seizures - Type II diabetes mellitus - Unsteady gait - Vertigo - 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. When do the diabetes and hearing loss associated with MIDD typically develop? In MIDD, the diabetes and hearing loss usually develop in mid-adulthood, although the age that they occur varies from childhood to late adulthood. Typically, hearing loss occurs before diabetes.
Source: GARD

Question: Is Maternally inherited diabetes and deafness inherited ?
Answer: How do people inherit MIDD? MIDD is inherited in a mitochondrial pattern, which is also known as maternal inheritance. This pattern of inheritance applies to genes contained in mitochondrial DNA. Because egg cells, but not sperm cells, contribute mitochondria to the developing embryo, only females pass mitochondrial conditions to their children. Mitochondrial disorders can appear in every generation of a family and can affect both males and females, but fathers do not pass mitochondrial traits to their children. Most of the body's cells contain thousands of mitochondria, each with one or more copies of mitochondrial DNA. These cells can have a mix of mitochondria containing mutated and unmutated DNA (heteroplasmy). The severity of MIDD is thought to be associated with the percentage of mitochondria with the mitochondrial DNA mutation.
Source: GARD