Preferred Label : Myotonia with skeletal abnormalities and impaired intellectual development;
Type : Other, mainly phenotypes with suspected mendelian basis;
Alternative titles and symbols : Myotonia with skeletal abnormalities and mental retardation;
Description : In 3 brothers and a sister out of 9 sibs of nonconsanguineous parents, Richieri-Costa
et al. (1984) described a progressive disorder with onset usually at a mean age of
5.7 years and including myotonia, progressive impairment of gait, alterations in the
thorax and vertebral column, short stature, and mild to moderate mental retardation.
The 15-year-old proband had 'painful spasms' in his legs and a progressively rigid
gait. He showed pectus carinatum and generalized muscular hypertrophy with a firm
consistency. Both spontaneous and elicited myotonia was found. A wedge deformity of
the first and second lumbar vertebra was demonstrated. The articular surfaces of the
acetabulum and the femoral epiphyses were also irregular. His 13-year-old brother
also had 'painful spasms,' pectus carinatum, pronounced muscular hypertrophy and firm
consistency of muscles, and kyphoscoliosis. Their affected 20-year-old brother was
only 139 cm tall. Wedge vertebra at the first and/or second lumbar level seemed to
be a consistent feature. Richieri-Costa et al. (1984) pointed to the lack of blepharophimosis
and small mouth and the presence of mental retardation as some of the features distinguishing
this disorder from Schwartz-Jampel syndrome (255800). Furthermore, they pointed out
that the Schwartz-Jampel syndrome usually starts in the first 2 years of life, whereas
the initial manifestations were later in this disorder. (For some reason, however,
they referred to the disorder as 'late infantile autosomal recessive myotonia' in
the title of their article.) *FIELD* RF 1. Richieri-Costa, A.; Garcia Da Silva, S.
M.; Frota-Pessoa, O.: Late infantile autosomal recessive myotonia, mental retardation,
and skeletal abnormalities: a new autosomal recessive syndrome. J. Med. Genet. 21:
103-107, 1984. *FIELD* CS Autosomal recessive;
Inheritance : Autosomal recessive;
Prefixed ID : 255710;
Origin ID : 255710;
UMLS CUI : C1850654;
Automatic exact mappings (from CISMeF team)
- Currated CISMeF NLP mapping
- HPO term(s)
- ORDO concept(s)
- Semantic type(s)
- UMLS correspondences (same concept)
