Lethal arthrogryposis with anterior horn cell disease (LAAHD) is an

autosomal An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosome, allosomal (sex chromosome) pairs, which may have different structures. The DNA in au ...

recessive In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...

genetic disorder A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders ...

characterized by reduced mobility of the

foetus A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal develo ...

and early death.

Presentation

LAAHD resembles LCCS1 disease but the

phenotype In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...

is milder, with survival beyond 32nd gestational week. However, the foetuses are often

stillborn Stillbirth is typically defined as fetal death at or after 20 or 28 weeks of pregnancy, depending on the source. It results in a baby born without signs of life. A stillbirth can result in the feeling of guilt or grief in the mother. The term i ...

or survive only few minutes. The movements of the foetus during pregnancy are scanty and stiff, often only in upper limbs. The malpositions are

distal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

. The inwards spiral and especially the elbow

contractures In pathology, a contracture is a permanent shortening of a muscle or joint. It is usually in response to prolonged hypertonic spasticity in a concentrated muscle area, such as is seen in the tightest muscles of people with conditions like spasti ...

are less severe than in LCCS1 disease. Some patients have intrauterine long bone fractures. Skeletal muscles are affected and show

neurogenic In Biology, biology, the nervous system is the Complex system, highly complex part of an animal that coordinates its Behavior, actions and Sense, sensory information by transmitting action potential, signals to and from different parts of its ...

atrophy Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations (which can destroy the gene to build up the organ), poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply t ...

. The size and shape of spinal cord at different levels are normal but anterior horn

motoneurons A motor neuron (or motoneuron or efferent neuron) is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, and whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly or indirectly ...

are diminished in number and degenerated.

Molecular genetics

LAAHD disease results from compound heterozygosity of GLE1FinMajor and a missense point mutation in exon 13 (6 cases in 3 families) or a missense mutation in exon 16 ( seven cases in 3 families). One of the latter cases survived 12 weeks, mostly under artificial respiration.

Diagnosis

Treatment

Epidemiology

LAAHD is one of approximately 40

Finnish heritage disease A Finnish heritage disease is a genetic disease or disorder that is significantly more common in people whose ancestors were ethnic Finns, natives of Finland and Sweden ( Meänmaa) and Russia ( Karelia and Ingria). There are 36 rare diseases regar ...

s. Families affected by these diseases come from different parts of

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

, and birthplaces of the ancestors of affected individuals do not show geographic clustering.

References

External links

{{Medical resources , ICD10 = , ICD9 = , ICDO = , OMIM = 611890 , DiseasesDB = , MedlinePlus = , eMedicineSubj = , eMedicineTopic = , MeSH = , GeneReviewsNBK = , GeneReviewsName = , Orphanet = 53696 Rare diseases Genetic disorders with no OMIM