Table 2.

Inheritance patterns among 670 positive cases

Mode of inheritance	No. of cases (%) N = 670
Autosomal recessive	530 (79.1%)
Homozygous	184
Apparently homozygousa	257
Compound heterozygous	27
Potential compound heterozygousa	23
Heterozygous in parent(s) of a deceased patient	39
Autosomal dominant	98 (14.6%)
De novo	46
Inherited from an affected parent	9
Parental gonadal mosaicism	4
Not studieda	39
X-linked	42 (6.3%)
X-linked recessive	32
De novo	3
Maternally inherited	15
Not studieda	14
X-linked dominant	10
De novo	5
Inherited from affected mother	3
Not studieda	2

^aParental inheritance was not determined due to the unavailability of samples.

^bIncludes two patients with both AD and AR disorders. cIncludes one patient with both XLD and AR disorders.