Traits

Traits linked to SDHB

succinate dehydrogenase complex iron sulfur subunit B

The Human Phenotype Ontology links 161 traits to SDHB, by body system: features seen in people with one of the gene's rare conditions.

Abnormality of the nervous system

Trait	How often it is seen
Delayed ability to stand	Always
Delayed ability to walk	Always
Elevated brain lactate level by MRS	Always
Falls	Always
Hyperintensity of cerebral white matter on MRI	Always
Increased reflexes	Always
Irritability	Always
Leukodystrophy	Always
Loss of developmental milestones	Always
Ataxia	Often (30–79%)
Babinski sign	Often (30–79%)
Brisk knee jerk	Often (30–79%)
Cranial nerve paralysis	Often (30–79%)
Dystonia	Often (30–79%)
Episodic paroxysmal anxiety	Often (30–79%)
Generalized myoclonic seizure	Often (30–79%)
Hyperactive deep tendon reflexes	Often (30–79%)
Motor delay	Often (30–79%)
Progressive degeneration of movement	Often (30–79%)
Progressive psychomotor deterioration	Often (30–79%)
Recurrent paroxysmal headache	Often (30–79%)
Upper limb hyperreflexia	Often (30–79%)
Cancer of early nerve cells	Sometimes (5–29%)
Communication delay	Sometimes (5–29%)
Cranial nerve compression	Sometimes (5–29%)
Delayed ability to sit	Sometimes (5–29%)
Delayed speech and language development	Sometimes (5–29%)
Epilepsy	Sometimes (5–29%)
Febrile seizure (within the age range of 3 months to 6 years)	Sometimes (5–29%)
Focal myoclonic seizure	Sometimes (5–29%)
Headache	Sometimes (5–29%)
Inability to move vocal cords	Sometimes (5–29%)
Moderate global developmental delay	Sometimes (5–29%)
Panic attack	Sometimes (5–29%)
Tremor	Sometimes (5–29%)
Dementia	Rarely (1–4%)
Loss of ability to walk	Rarely (1–4%)

Abnormality of the cardiovascular system

Trait	How often it is seen
Abnormal left ventricular function	Often (30–79%)
Abnormality of the cardiovascular system	Often (30–79%)
Decrease in blood pressure upon standing up	Often (30–79%)
Elevated heart rate	Often (30–79%)
Enlarged and thickened heart muscle	Often (30–79%)
Fainting spell	Often (30–79%)
High blood pressure	Often (30–79%)
Hypertension associated with pheochromocytoma	Often (30–79%)
Hypertensive retinopathy	Often (30–79%)
Left ventricular hypertrophy	Often (30–79%)
Palpitations	Often (30–79%)
Positive regitine blocking test	Often (30–79%)
Sinus tachycardia	Often (30–79%)
Swollen lymph nodes in center of chest	Often (30–79%)
Abnormal atrioventricular conduction	Sometimes (5–29%)
Abnormal heart rate	Sometimes (5–29%)
Arachnoid hemangiomatosis	Sometimes (5–29%)
Cardiac failure	Sometimes (5–29%)
Disease of the heart muscle	Sometimes (5–29%)
Hypertensive crisis	Sometimes (5–29%)
Inflammation of heart muscle	Sometimes (5–29%)
Noncompaction cardiomyopathy	Sometimes (5–29%)
Swollen lymph nodes	Sometimes (5–29%)
Hives	Not recorded

Abnormality of the digestive system

Trait	How often it is seen
Feeding difficulties in infancy	Always
Abdominal pain	Very often (80–99%)
Diarrhea	Very often (80–99%)
Gastrointestinal stroma tumor	Very often (80–99%)
Nausea and vomiting	Very often (80–99%)
Stomach tumor	Very often (80–99%)
Accumulation of fluid in the abdomen	Often (30–79%)
Constipation	Often (30–79%)
Intermittent abdominal pain	Often (30–79%)
Intestinal obstruction	Often (30–79%)
Nausea	Often (30–79%)
Poor swallowing	Often (30–79%)
Abdominal mass	Sometimes (5–29%)
Abnormality of the liver	Sometimes (5–29%)
Anorexia	Sometimes (5–29%)
Colon tumor	Sometimes (5–29%)
Esophageal tumor	Sometimes (5–29%)
Gastrointestinal tract tumor	Sometimes (5–29%)
Rectal tumor	Sometimes (5–29%)
Small intestine tumor	Sometimes (5–29%)

Abnormality of the musculoskeletal system

Trait	How often it is seen
Flexed joint that cannot be straightened	Always
Generalized decreased muscle tone	Always
Low muscle tone	Always
Poor head control	Always
Involuntary muscle stiffness, contraction, or spasm	Very often (80–99%)
Low muscle tone in trunk	Very often (80–99%)
Distal muscle wasting	Often (30–79%)
Generalized muscle weakness	Often (30–79%)
Proximal neurogenic muscle weakness	Often (30–79%)
Skeletal myopathy	Often (30–79%)
Tired easily	Often (30–79%)
Frequent falls	Sometimes (5–29%)
Muscle degeneration	Sometimes (5–29%)
Spastic paraparesis	Sometimes (5–29%)
Spastic tetraparesis	Sometimes (5–29%)

Laboratory abnormality

Trait	How often it is seen
Higher than normal levels of lactate in blood	Always
Increased circulating pyruvate concentration	Always
Increased urine alpha-ketoglutarate concentration	Always
Elevated urinary dopamine	Often (30–79%)
Elevated urinary epinephrine level	Often (30–79%)
Elevated urinary norepinephrine level	Often (30–79%)
High blood calcium levels	Often (30–79%)
High urine protein levels	Often (30–79%)
Blood in urine	Sometimes (5–29%)
Elevated calcitonin	Sometimes (5–29%)
High blood sugar	Sometimes (5–29%)
Elevated urinary catecholamines	Not recorded

Abnormality of the endocrine system

Trait	How often it is seen
Adrenal pheochromocytoma	Very often (80–99%)
Extraadrenal pheochromocytoma	Very often (80–99%)
Paraganglioma	Very often (80–99%)
Pheochromocytoma	Very often (80–99%)
Adrenal overactivity	Often (30–79%)
Adrenocortical adenoma	Often (30–79%)
Paraganglioma of head and neck	Often (30–79%)
Chemodectoma	Not recorded
Glomus jugular tumor	Not recorded

Abnormality of the eye

Trait	How often it is seen
Abnormality of the eye	Often (30–79%)
Decreased clarity of vision	Often (30–79%)
Absent iris	Rarely (1–4%)
Blindness	Rarely (1–4%)
Involuntary, rapid, rhythmic eye movements	Rarely (1–4%)
Paralysis or weakness of muscles within or surrounding outer part of eye	Rarely (1–4%)
Pigmentary retinopathy	Rarely (1–4%)

Abnormality of the integument

Trait	How often it is seen
Flushing	Often (30–79%)
Sporadic excessive sweating	Often (30–79%)
Irregular hyperpigmentation	Sometimes (5–29%)
Paleness	Sometimes (5–29%)
Excessive sweating	Not recorded
Neurofibroma	Not recorded
Patchy darkened skin	Not recorded

Abnormality of the ear

Trait	How often it is seen
Hearing impairment	Often (30–79%)
Paroxysmal vertigo	Often (30–79%)
Pulsatile tinnitus	Often (30–79%)
Ringing in ears	Often (30–79%)
Conductive deafness	Sometimes (5–29%)

Abnormality of the genitourinary system

Trait	How often it is seen
Glomerular sclerosis	Often (30–79%)
Cancer starting in small tubes in kidneys	Sometimes (5–29%)
Renal failure	Sometimes (5–29%)
Vesicoureteral reflux	Rarely (1–4%)

Growth abnormality

Trait	How often it is seen
Proportionate short stature	Often (30–79%)
Severe short stature	Often (30–79%)
Weight loss	Often (30–79%)
Prenatal growth deficiency	Sometimes (5–29%)

Abnormality of blood and blood-forming tissues

Trait	How often it is seen
Gastrointestinal bleeding	Very often (80–99%)
Bleeding in brain	Often (30–79%)
Low number of red blood cells or hemoglobin	Sometimes (5–29%)

Abnormality of head or neck

Trait	How often it is seen
Abnormally small head	Sometimes (5–29%)
Mild microcephaly	Sometimes (5–29%)
Retinal capillary hemangioma	Sometimes (5–29%)

Abnormality of limbs

Trait	How often it is seen
Inability to straighten knee	Sometimes (5–29%)
Lower limb hypertonia	Sometimes (5–29%)
Large hands	Not recorded

Abnormal tissue mass

Trait	How often it is seen
Cancer of connective tissue	Very often (80–99%)
Leiomyosarcoma	Very often (80–99%)

Constitutional symptom

Trait	How often it is seen
Fatigue	Very often (80–99%)
Chest pain	Often (30–79%)

Abnormal cellular phenotype

Trait	How often it is seen
Decreased activity of mitochondrial complex II	Always

Abnormality of the immune system

Trait	How often it is seen
Skin rash	Sometimes (5–29%)

Abnormality of the respiratory system

Trait	How often it is seen
Lung infiltrates	Often (30–79%)

Abnormality of the voice

Trait	How often it is seen
Inability to produce voice sounds	Often (30–79%)

How often is among people with one of the gene's conditions, the most often across them, as the Human Phenotype Ontology records it. These pages describe traits and the research behind them; they are not a diagnosis, and a doctor or genetic counsellor is the person to ask about symptoms.

Where this comes from

The Human Phenotype Ontology, release 2026-09-01: the traits linked to SDHB and how often each is seen. Find out more at hpo.jax.org.

One test. A lifetime of answers.

From $449Free shipping · Results in 6–8 weeks

Get my Genome Test