Explaining to others

NDM is a rare disease, which only affects around 1 in every 100,000 people worldwide,1 and can take several years to be diagnosed.2 Consequently, people around you may never have heard of your condition and may not understand some of the challenges you face.

People with NDM experience myotonia (muscle stiffness, cramps or locking) during everyday tasks and activities, and may also experience pain and fatigue.1,3 Symptoms usually begin in childhood or early adulthood4 and will continue throughout a person’s life. Therefore, it is important to learn how to talk to people about NDM.

You can download a factsheet on NDM to share with your family, friends, school or employers. The factsheet may help you explain to others that the symptoms you experience are caused by a condition that you have inherited through your genes.

There are strategies to help you manage the symptoms of NDM but these may also need to be discussed with those around you. For example, if you or your child is in school or college, explain to teachers that you may need to “warm up” after sitting still for long periods of time, or that you may need additional help during sports lessons.

Explaining NDM to your employers can open discussions about how to adapt any tasks that you may find difficult and make things easier if you need to attend medical appointments.

References
  • Hahn C, Salajegheh MK. Iran J Neurol 2016;15:46–53
  • Vereb N. J Neurol. 2021; 268(5): 1708–1720
  • Trip J, et al. J Neurol 2009;256:939–947
  • Matthews E, et al. Pract Neurol 2021;0:1-10

What’s your NDM story?

speech

Share your story of your journey with NDM here

You are free to share your story in writing, video, audio, painting, or any other form that helps you tell your story about your journey with NDM.

Foods to avoid on a low-potassium diet*

  • Fruit1,2
  • Vegetables1,2
  • Beans/legumes1,3
  • Other1-3
  • Avocado
  • Artichoke
  • Baked beans
  • Bran cereal
  • Apricots
  • Beetroot
  • Kidney beans
  • Dairy (eg yoghurt, milk)
  • Bananas
  • Brussel sprouts
  • Lentils
  • Nuts
  • Dried fruits eg dates, raisins and prunes
  • Broccoli (cooked)
  • Brown rice
  • Grapefruit
  • Okra
  • Salt substitutes
  • Kiwi
  • Parsnip
  • Wholewheat bread and pasta
  • Mango
  • Potatoes (processed or with skin on)
  • Melons
  • Cooked spinach
  • Nectarines
  • Tomato (concentrated, eg. Tomato puree)
  • Oranges and orange juice
  • Papaya
  • Pomegranate and pomegranate juice
  • Fruit1,2

    Avocado

    Apricots

    Bananas

    Dried fruits eg dates, raisins and prunes

    Grapefruit

    Kiwi

    Mango

    Melons

    Nectarines

    Oranges and orange juice

    Papaya

    Pomegranate and pomegranate juice

  • Vegetables1,2

    Artichoke

    Beetroot

    Brussel sprouts

    Broccoli (cooked)

    Okra

    Parsnip

    Potatoes (processed or with skin on)

    Cooked spinach

    Tomato (concentrated, eg. Tomato puree)

  • Beans/legumes1,3

    Baked beans

    Kidney beans

    Lentils

  • Other1-3

    Bran cereal

    Dairy (eg yoghurt, milk)

    Nuts

    Brown rice

    Salt substitutes

    Wholewheat bread and pasta

*Meat and fish contain a moderate amount of potassium but they are an important source of protein so shouldn’t be avoided; Dairy products contain potassium but are an important source of calcium so should be consumed in moderation
References
  • WebMD. Low-potassium diet: what to know? Available at: https://www.webmd.com/food-recipes/low-potassium-diet-foods ; Accessed March 2021
  • St Georges Kidney Patients Association. Eating on a low potassium diet. Available at: https://www.sgkpa.org.uk/main/eating-well-on-a-low-potassium-diet-2 ; Accessed March 2021
  • NHS. Information for people on a low potassium diet. Available at: https://www.nth.nhs.uk/content/uploads/2019/02/PIL1061-Information-for-people-following-a-low-potassium-diet-Final-11.02.19-LP.pdf ; Accessed March 2021
  • NDM type1
  • Symptoms2,3
  • Which type of ion channel? 2,3
  • How is it inherited?2,3
  • Thomsen myotonia congenita

    (also called Thomsen myotonia or autosomal dominant myotonia congenita)
  • Lower limbs tend to be more affected, although can also affect the arms, hands and face. Stiffness may be worse when you first try to move after a period of inactivity, and may ease as you ‘warm up’.
  • Chloride (Cl-)
  • Autosomal dominant
  • Becker myotonia congenita

    (also called Becker myotonia, Becker disease, generalized myotonia, recessive generalized myotonia or autosomal recessive myotonia congenita
  • Lower limbs tend to be more affected, although can also affect the arms, hands and face. Stiffness may be worse when you first try to move after a period of inactivity, or if you are startled, and may ease as you ‘warm up’. Sometimes people with Becker myotonia congenita experience temporary weakness after an episode of myotonia.
  • Chloride (Cl-)
  • Autosomal recessive
  • Paramyotonia congenita

    (Also called Eulenburg disease, paralysis periodica paramyotonia, paramyotonia congenita of von Eulenburg, PMC or von Eulenburg’s disease)
  • Myotonia mainly affects hands and face and gets worse with exercise. Cold is also a key trigger of myotonia, and muscle weakness after an episode of myotonia may last hours or sometimes days.
  • Sodium (Na+)
  • Autosomal dominant
  • Sodium channel myotonia, SCM:

    myotonia permanens and myotonia fluctuans, acetazolamide-responsive myotonia (ARM) previously known as Potassium aggravated myotonias (PAM)
  • Potassium-aggravated myotonia is a rare form of NDM that affects all areas of the body. Myotonia attacks are triggered by eating potassium-rich foods. Symptoms may fluctuate widely from day to day (myotonia fluctuans) or are constant and severe (myotonia permanens).
  • Sodium (Na+)
  • Autosomal dominant
  • Other closely related sodium disorders with myotonia

    (including hyperkalemic paralysis or hyperPP)
  • Myotonia is usually mild, and often involves the eyelids, hands, and tongue. Attacks of weakness can occur at any time and are commonly triggered by rest following exercise, fasting, eating potassium-rich foods or stress.
  • Sodium (Na+)
  • Autosomal dominant
References
  • Stunnenberg B. Muscle Nerve. 2020 Oct; 62(4): 430–444
  • Hahn C, Salajegheh MK. Iran J Neurol 2016;15:46–53
  • Matthews E, et al. Brain 2010:133; 9–22
  • NDM type1

    Thomsen myotonia congenita

    (also called Thomsen myotonia or autosomal dominant myotonia congenita)

    Becker myotonia congenita

    (also called Becker myotonia, Becker disease, generalized myotonia, recessive generalized myotonia or autosomal recessive myotonia congenita

    Paramyotonia congenita

    (Also called Eulenburg disease, paralysis periodica paramyotonia, paramyotonia congenita of von Eulenburg, PMC or von Eulenburg’s disease)

    Sodium channel myotonia, SCM:

    myotonia permanens and myotonia fluctuans, acetazolamide-responsive myotonia (ARM) previously known as Potassium aggravated myotonias (PAM)

    Other closely related sodium disorders with myotonia

    (including hyperkalemic paralysis or hyperPP)

  • Symptoms2,3

    Lower limbs tend to be more affected, although can also affect the arms, hands and face. Stiffness may be worse when you first try to move after a period of inactivity, and may ease as you ‘warm up’.

    Lower limbs tend to be more affected, although can also affect the arms, hands and face. Stiffness may be worse when you first try to move after a period of inactivity, or if you are startled, and may ease as you ‘warm up’. Sometimes people with Becker myotonia congenita experience temporary weakness after an episode of myotonia.

    Myotonia mainly affects hands and face and gets worse with exercise. Cold is also a key trigger of myotonia, and muscle weakness after an episode of myotonia may last hours or sometimes days.

    Potassium-aggravated myotonia is a rare form of NDM that affects all areas of the body. Myotonia attacks are triggered by eating potassium-rich foods. Symptoms may fluctuate widely from day to day (myotonia fluctuans) or are constant and severe (myotonia permanens).

    Myotonia is usually mild, and often involves the eyelids, hands, and tongue. Attacks of weakness can occur at any time and are commonly triggered by rest following exercise, fasting, eating potassium-rich foods or stress.

  • Which type of ion channel? 2,3

    Chloride (Cl-)

    Chloride (Cl-)

    Sodium (Na+)

    Sodium (Na+)

    Sodium (Na+)

  • How is it inherited?2,3

    Autosomal dominant

    Autosomal recessive

    Autosomal dominant

    Autosomal dominant

    Autosomal dominant

References
  • Stunnenberg B. Muscle Nerve. 2020 Oct; 62(4): 430–444
  • Hahn C, Salajegheh MK. Iran J Neurol 2016;15:46–53
  • Matthews E, et al. Brain 2010:133; 9–22